WCOB Data Analysis Units 1-4 Review Aguiar

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In this scenario, which of the following would be a TYPE II error? A. Failing to reject the null hypothesis and concluding that Netflix would not lose money because of the rate hike when, in fact, they would lose money. B. Rejecting the null hypothesis and concluding that Netflix would not lose money because of the rate hike when, in fact, they would lose money. C. Failing to reject the null hypothesis and concluding that Netflix would lose money because of the rate hike when, in fact, they would not lose money. D. Rejecting the null hypothesis and concluding that Netflix would lose money because of the rate hike when, in fact, they would not lose money.

A. Failing to reject the null hypothesis and concluding that Netflix would not lose money because of the rate hike when, in fact, they would lose money.

A production filling operation has a historical standard deviation of 6 ounces. When in perfect adjustment, the mean filling weight for the production process is 50 ounces. A quality control inspector periodically randomly selects 36 containers and uses the sample mean filling weight to see if the process is in perfect adjustment. He finds that the sample mean is 48.6 ounces. Null hypothesis: m = 50 Alternate hypothesis: m ≠ 50 In this problem, which of the following would be an example of a type I error? A. Rejecting the null hypothesis and concluding that the machine is not in perfect adjustment when, in fact, it is in perfect adjustment. B. Rejecting the null hypothesis and concluding that the machine is not in perfect adjustment when, in fact, it is not in perfect adjustment. C. Failing to reject the null hypothesis and concluding that the machine is in perfect adjustment when, in fact, it is in perfect adjustment. D. Failing to reject the null hypothesis and concluding that the machine is in perfect adjustment when, in fact, it is not in perfect adjustment.

A. Rejecting the null hypothesis and concluding that the machine is not in perfect adjustment when, in fact, it is in perfect adjustment.

Goodyear advertises that the average life of their snow tires in Salt Lake City is 60 months. The publisher of Consumer Reports surveyed ten randomly selected people who bought the tires several years ago. The mean reported life of the tires of these ten respondents is 54 months. Assuming that the life of snow tires is normally distributed with a standard deviation of 5 months, test the hypothesis that Goodyear tires last an average of 60 months. Null hypothesis: m = 60 Alternate hypothesis: m ≠ 60 In this scenario, which of the following is a TYPE II error? A. Reject H0 and conclude the average life of Goodyear tires equals 60 months, when in fact, it does not B. Fail to reject H0 and conclude the average life of Goodyear tires equals 60 months, when in fact, it does not C. Reject H0 and conclude the average life of Goodyear tires does not equal 60 months, when in fact, it does D. Fail to reject H0 and conclude the average life of Goodyear tires does not equal 60 months, when in fact, it does

B. Fail to reject H0 and conclude the average life of Goodyear tires equals 60 months, when in fact, it does not

On average, students with a major from the Walton College of Business (WCOB) take four months to find a job after graduation. The Dean has suggested that the WCOB could decrease the average time it takes graduates to find jobs by placing more students in internships. Therefore, the WCOB partnered with several local and national businesses to place undergraduates in internships that are relevant to their majors. A sample of 25 members of the first class involved in this program took an average of 3.25 months to find a job with a standard deviation of 2.0 months. Null hypothesis: μ = 4 Alternate hypothesis: μ < 4 In this problem, which of the following would be a type II error? A. Rejecting the null hypothesis and concluding that the internship program decreases the amount of time that it takes students to find jobs when, in fact, it does. B. Rejecting the null hypothesis and concluding that the internship program decreases the amount of time that it takes students to find jobs when in fact, it does not. C. Failing to reject the null hypothesis and conclude that the internship program does not decrease the amount of time that it takes students to find jobs when in fact, it does not. D. Failing to reject the null hypothesis and conclude that the internship program does not decrease the amount of time that it takes students to find jobs when, in fact, it does.

D. Failing to reject the null hypothesis and conclude that the internship program does not decrease the amount of time that it takes students to find jobs when, in fact, it does.

A production filling operation has a historical standard deviation of 6 ounces. When in perfect adjustment, the mean filling weight for the production process is 50 ounces. A quality control inspector periodically randomly selects 36 containers and uses the sample mean filling weight to see if the process is in perfect adjustment. He finds that the sample mean is 48.6 ounces. Null hypothesis: m = 50 Alternate hypothesis: m ≠ 50 In this problem, which of the following would be an example of a type II error? A. Rejecting the null hypothesis and concluding that the machine is not in perfect adjustment when, in fact, it is in perfect adjustment. B. Rejecting the null hypothesis and concluding that the machine is not in perfect adjustment when, in fact, it is not in perfect adjustment. C. Failing to reject the null hypothesis and concluding that the machine is in perfect adjustment when, in fact, it is in perfect adjustment. D. Failing to reject the null hypothesis and concluding that the machine is in perfect adjustment when, in fact, it is not in perfect adjustment.

D. Failing to reject the null hypothesis and concluding that the machine is in perfect adjustment when, in fact, it is not in perfect adjustment.

Goodyear advertises that the average life of their snow tires in Salt Lake City is 60 months. The publisher of Consumer Reports surveyed ten randomly selected people who bought the tires several years ago. The mean reported life of the tires of these ten respondents is 54 months. Assuming that the life of snow tires is normally distributed with a standard deviation of 5 months, test the hypothesis that Goodyear tires last an average of 60 months. Null hypothesis: ________________ Alternate hypothesis: ________________ In this scenario, which of the following is a TYPE I error? A. Reject H0 and conclude the average life of Goodyear tires equals 60 months, when in fact, it does not B. Fail to reject H0 and conclude the average life of Goodyear tires equals 60 months, when in fact, it does not C. Reject H0 and conclude the average life of Goodyear tires does not equal 60 months, when in fact, it does D. Fail to reject H0 and conclude the average life of Goodyear tires does not equal 60 months, when in fact, it does

Null hypothesis: m = 60 Alternate hypothesis: m ≠ 60 C. Reject H0 and conclude the average life of Goodyear tires does not equal 60 months, when in fact, it does

Reed Hastings, the CEO of Netflix, is considering raising subscription prices (again). David Wells, the chief financial officer, warns that Netflix will lose money in the long run if more than 7% of current customers cancel their subscriptions because of the rate hike. To assess the possibility that Netflix will lose money, the marketing department surveyed 50 male and 50 female customers and matched the customers on how long they had subscribed to Netflix. Four women and five men indicated they would drop their membership if Netflix raised its rates. Based on these results, is it likely that Netflix will lose money because of the rate increase? Null hypothesis: ______________ Alternate hypothesis: _____________ In this scenario, which of the following would be a TYPE I error? A. Failing to reject the null hypothesis and concluding that Netflix would not lose money because of the rate hike when, in fact, they would lose money. B. Rejecting the null hypothesis and concluding that Netflix would not lose money because of the rate hike when, in fact, they would lose money. C. Failing to reject the null hypothesis and concluding that Netflix would lose money because of the rate hike when, in fact, they would not lose money. D. Rejecting the null hypothesis and concluding that Netflix would lose money because of the rate hike when, in fact, they would not lose money.

Null hypothesis: p = .07 Alternate hypothesis: p > .07 D. Rejecting the null hypothesis and concluding that Netflix would lose money because of the rate hike when, in fact, they would not lose money.

On average, students with a major from the Walton College of Business (WCOB) take four months to find a job after graduation. The Dean has suggested that the WCOB could decrease the average time it takes graduates to find jobs by placing more students in internships. Therefore, the WCOB partnered with several local and national businesses to place undergraduates in internships that are relevant to their majors. A sample of 25 members of the first class involved in this program took an average of 3.25 months to find a job with a standard deviation of 2.0 months. Null hypothesis: ________________ Alternate hypothesis: ________________ In this problem, which of the following would be a type I error? A. Rejecting the null hypothesis and concluding that the internship program decreases the amount of time that it takes students to find jobs when, in fact, it does. B. Rejecting the null hypothesis and concluding that the internship program decreases the amount of time that it takes students to find jobs when, in fact, it does not. C. Failing to reject the null hypothesis and conclude that the internship program does not decrease the amount of time that it takes students to find jobs when, in fact, it does not. D. Failing to reject the null hypothesis and conclude that the internship program does not decrease the amount of time that it takes students to find jobs when, in fact, it does.

Null hypothesis: μ = 4 Alternate hypothesis: μ < 4 B. Rejecting the null hypothesis and concluding that the internship program decreases the amount of time that it takes students to find jobs when, in fact, it does not.

The average annual cost of tuition at Sunshine State University is normally distributed with a mean of $18,695 and a standard deviation of $2,163. In an unfortunate accident, Sunshine State University lost all of their tuition cost records. To determine the annual cost of tuition, administrators sampled 49 undergraduate students and found that the annual cost of tuition is normally distributed with a mean of $19,354 and a standard deviation of $4,579. What is the estimated interval for μ at a 90 percent confidence level? a. $18,257, $20,451 b. $18,278, $20,430 c. $18,504, $20,204 d. $18,514, $20,194

a. $18,257, $20,451

The mileage (i.e., miles per gallon) of a brand of hybrid automobiles is a normally distributed variable with a mean (µ) of 60 and a standard deviation (σ) of 3. Suppose that 10 automobiles are chosen at random. What is the probability that the mean mileage of these automobiles will be less than 55? a. 0.0000 b. 0.3531 c. 0.6305 d. 0.8541

a. 0.0000

Which p-values will lead us to reject the null hypothesis if the significance level equals 0.10? a. 0.05 b. 0.11 c. 0.15 d. 0.25

a. 0.05

Exam scores on last year's Data Analysis final were normally distributed, with a mean (μ) of 67 and a standard deviation (σ) of 12. Letter grades for the exam were based on a classic scale, with 90-100 = A; 80-89 = B; 70-79 = C; 60-69 = D; below 60 = F. 10. If you took a random sample of the 36 students from last year's data analysis class final exam, what is the probability that the mean of their scores was greater than 70? a. 0.0668 b. 0.1587 c. 0.4013 d. 0.6332

a. 0.0668

The Chartered Financial Analyst (CFA) Institute reported that 64% of its U.S. members indicate that a lack of ethical culture within financial firms has contributed the most to the lack of trust in the financial industry. 14. Suppose you select a random sample of 100 CFA members; 70 reported that the lack of ethical culture within financial firms had contributed the most to the lack of trust in the financial industry. Based on a 95% confidence interval, which of the below is most unlikely to be the estimated population proportion based on this sample? a. 0.60 b. 0.65 c. 0.70 d. 0.75

a. 0.60

If the mean of a dataset is 25 and the standard deviation is 5, compute the coefficient of variation a. 20% b. 5% c. 15% d. There is not enough information provided

a. 20%

If the standard deviation of a set of data is 5, what is the variance? a. 25 b. 50 c. 75 d. There is not enough information provided

a. 25

A few weeks ago, I surveyed members of this class to see how many hours students worked in the Walton College. Assume that students in my two classes are representative of Walton College students. I obtained the following statistics. Mean 11.34615 Standard Error 1.736546 Standard Deviation 15.33676 Sample Variance 235.2163 Kurtosis -0.04853 Skewness 1.082437 Range 55 Sum 885 Count 78 Referring to this output, which of the following is the 95% confidence interval estimate of the mean work hours of all Walton College students? a. 7.8882 - 14.8041 b. 8.4650 - 14.2473 c. 6.7696 - 15.9427 d. 9.1114 - 13.6009 How would the results be different if you used a 90% confidence interval? a. The interval would be about the same due to the small sample size. b. The interval would be wider. c. The interval would be smaller. d. Not enough information provided to answer the question.

a. 7.8882 - 14.8041 c. The interval would be smaller.

A manager runs a store that serves about 250,000 customers. He wants to know some information about them, so he conducts a survey. One of the questions he asks for this survey is: "Which of the following is the most important reason for buying your groceries at this store? (Choose one) ___ meat quality ___ low prices ____ produce quality ____ service quality What kind of a measure is this question? a. A nominal variable b. An ordinal variable c. An integer variable d. A standard normal variable

a. A nominal variable

Dr. Jones wants to do an analysis on students' final examination scores in her math class for the past year. She should consider her data to be: a. A population b. A sample c. A standard normal distribution d. None of the above

a. A population

In testing the hypotheses below, you find that Zcrit = -1.85 and Zstat = -1.65. What is the correct decision? HO: µ ≥ 930 H1 : µ < 930 a. Fail to reject HO b. Reject HO c. Fail to Retain H1 d. Retain H1

a. Fail to reject HO

Using the sample mentioned in question (92), you want to estimate if the population proportion of members indicating that lack of ethical culture within financial firms has contributed the most to the lack of trust in the financial industry is higher than the CFA's reported 64%. which of the following would be the proper hypotheses? a. H0 : π ≤ .64, H1 : π > .64 b. H0 : π = .64, H1 : π ≠ .64 c. H0 : π ≤ .70, H1 : π > .70 d. H0 : μ ≤ 64, H1 : μ > 64

a. H0 : π ≤ .64, H1 : π > .64

A car sales lot has decided to use a customer satisfaction survey to learn more information about people who have recently purchased cars from them. From existing records, management knows that the distribution of the amount spent per customer has a highly positive skew with a mean of $17,000. What sort of graph would you use to illustrate the amount customers spend on cars at the car lot? a. Histogram b. Pie Chart c. Scatter diagram d. Stem-and-leaf plot

a. Histogram

Use the following scenario to answer the next three questions. A manager of a recording company wants to know if UA students are typical of other college students in terms of whether they will subscribe to a music service for $7.99 per month. Nationally, he knows that 12% will do so. He randomly samples 400 UA students and asks them if they would subscribe for $7.99 monthly. He codes their responses (1=yes, 2=no). 1. Which of the following is the proper set of hypotheses? a. Ho: π = .12 H1: π ≠ .12 b. Ho: π ≠ .12 H1: π > .12 c. Ho: μ = .12 H1: μ ≠ .12 d. Ho: μ = .12 H1: μ > .12

a. Ho: π = .12 H1: π ≠ .12

USPS asked customers to report their satisfaction with the new shipping prices (Very Satisfied, Satisfied, Dissatisfied, Very Dissatisfied). What type of data is customer satisfaction? a. Ordinal b. Ratio c. Nominal d. Correlational

a. Ordinal

The current price of crude oil is $59. What type of scale is used to measure the price of the crude oil? a. Ratio b. Interval c. Ordinal d. Nominal

a. Ratio

Time series data consist of observations of a single subject at multiple time intervals; cross-sectional data consists of observations of many subjects at one point in time. a. True b. False

a. True

Which of the following statements is true? a. With probability sampling methods, each population element has a known (non-zero) chance of being chosen for the sample. b. With probability sampling methods, we do not know the probability that each population element will be chosen, and/or we cannot be sure that each population element has a non-zero chance of being chosen. c. With nonprobability sampling methods, each population element has a known (non-zero) chance of being chosen for the sample. d. None of these statements is true.

a. With probability sampling methods, each population element has a known (non-zero) chance of being chosen for the sample.

Paul and Sharon Jones, co-owners of a shopping mall, are interested in studying the purchasing patterns of their shoppers. They measure how long shoppers are in the mall and how much money they spend per hour. Based on a sample of 60 shoppers, they find that the shoppers spend, on average, $54 per hour of shopping. We can assume that the amount spent per hour of shopping is normally distributed with a standard deviation of $21. Calculate a 95% confidence interval for the population mean of the amount of money shoppers spend per hour of shopping. a. [48.69, 59.31] b. [50.53, 57.47] c. [49.47, 58.53] d. [49.60, 58.40]

a. [48.69, 59.31]

When data are collected in a statistical study for only a portion or subset of all elements of interest, we are using: a. a sample b. a parameter c. a population d. Both b and c

a. a sample

(relates to previous question) What is the p-value of the test statistic for testing the hypothesis stated in question 32? a. about 0.001 b. about 0.002 c. about 0.302 d. about 0.604

a. about 0.001

(relates to previous questions) What is the p-value of the test statistic needed to test the correct hypothesis? a. about 0.1 b. about 0.2 c. about 0.6 d. about 0.8

a. about 0.1

A study of waiting times at fast-food restaurants conducted by The Morning News in October of 2006 showed that the average waiting time (µ) to get food after placing an order at McDonald's, Burger King, and Wendy's was 85 seconds. Assume that waiting times are normally distributed and that the standard deviation (σ) equals 20 seconds. If you took a random sample of 25 customers from a fast-food restaurant, what is the probability that their mean wait time was greater than 93 seconds? a. about 2% b. about 4% c. about 19% d. about 34%

a. about 2%

The major problem with battery powered cars is the limited time they can be driven before the batteries must be recharged. StuckPedal Motors has developed a battery pack that will power a car at a sustained speed of 45 miles per hour for an average of 8 hours with a standard deviation of 0.4 hours. What is the likelihood that 10 randomly chosen cars equipped with the StuckPedal battery pack will be able to travel at 45 miles per hour for more than 8.4 hours on average? a. less than 1% b. about 16% c. about 34 % d. about 99%

a. less than 1%

Mean = 12.50 Standard Error = 0.42 Median = 13 Mode = 13 Standard Deviation = 2.50 Sample Variance = 6.26 Range = 9 Min = 8 Max = 17 Sum = 450 Count = 36 What happens to the confidence interval if the manager were to sample 50 additional employees? a. the confidence interval narrows b. the confidence interval widens c. the width of the confidence interval does not change d. the confidence interval becomes more normal

a. the confidence interval narrows

Which of the following formulas to calculate margin of error IS CORRECT? a. z * (σ / √n) b. t * (σ / √n) c. σ * (z / √n) d. σ * (t / √n)

a. z * (σ / √n)

The average annual cost of tuition at Sunshine State University is normally distributed with a mean of $18,695 and a standard deviation of $2,163. A sample of 25 students shows that the mean annual tuition cost is $17,954. Assuming that the sample is from a normal population, what is the 95% confidence interval for the true population mean? a. $17,061, $18,847 b. $17,106, $18,802 c. $17,242, $18,666 d. $17,784, $18,124

b. $17,106, $18,802

b. (46.02, 51.18)

Which of the following correlation coefficients indicates the STRONGEST correlation? a. 0.20 b. -0.60 c. 0.55 d. -0.15

b. -0.60

A simple random sample of 100 observations was drawn from a normal population. The mean and standard deviation of the sample were 120 and 25, respectively. To test the following hypotheses, with a = .10 Ho: μ = 125 H1: μ ≠ 125 Which of the following is the correct value of the test statistic? a. -20 b. -2.0 c. -.20 d. There is not enough information to decide.

b. -2.0

Which of the following p-values will lead us to reject the null hypothesis if the significance level equals 0.05? a. 0.15 b. 0.025 c. 0.10 d. 0.053

b. 0.025

The United States Postal Service (USPS) now offers a service that allows customers to ship packages at a flat rate based on box size (small, medium, large) rather than by weight. The USPS records the weight of all small packages shipped using this new service and finds a normally distributed variable with a mean of 6.9 pounds and a standard deviation of .63 pounds. What is the likelihood that average weight of 100 randomly selected small packages will be more than 7.0 pounds? a. 0.0000 b. 0.0562 c. 0.5000 d. 0.9441

b. 0.0562

Exam scores on last year's Data Analysis final were normally distributed, with a mean (μ) of 67 and a standard deviation (σ) of 12. Letter grades for the exam were based on a classic scale, with 90-100 = A; 80-89 = B; 70-79 = C; 60-69 = D; below 60 = F. 10. If you took a random sample of the 36 students from last year's data analysis class final exam, what is the probability that the mean of their scores was less than 65? a. 0.0668 b. 0.1587 c. 0.4013 d. 0.6332

b. 0.1587

Compute the range of the following data: 5 3 4 a. 1 b. 2 c. 3 d. The data does not have a range

b. 2

Compute the mean of the following data: 5 3 4 a. 3 b. 4 c. 5 d. The data does not have a mean

b. 4

Compute the median of the following data: 5 3 4 a. 3 b. 4 c. 5 d. The data does not have a median

b. 4

If the variance of a set of data is 64, what is the standard deviation? a. 6 b. 8 c. 9 d. There is not enough information provided

b. 8

A local bakery makes bagels that are supposed to weigh 100 grams (each). The standard deviation for the bagel making process is known to be 11 grams. You weight a sample of 49 bagels and find that the mean weight of a bagel is 99.5 grams. Assuming that the sample is from a normal population, what is the 80% confidence interval for the true population mean? a. 96.46, 102.50 b. 97.49, 101.51 c. 98.48, 103.52 d. 99.20, 99.80

b. 97.49, 101.51

A data analysis professor surveys 100 of his freshmen students to determine the number of pets in each student's household. He plans to compute statistical findings on the data and generalize these findings to the homes of all freshmen students. He should consider his data to be: a. A population b. A sample c. A standard normal distribution d. None of the above

b. A sample

A manager runs a store that serves about 250,000 customers. He wants to know some information about them, so he conducts a survey. One of the questions he asks for this survey is: "How many times per month do you shop for groceries at this store?" If he surveys 300 of his customers as they leave his store over a period of three different days these data would be considered: a. A population b. A sample c. A standard normal distribution d. None of the above

b. A sample

How do descriptive and inferential statistics differ? a. Inferential statistics attempts to describe data, while descriptive statistics attempts to make predictions based on data. b. Descriptive statistics attempts to describe data, while inferential statistics attempts to make predictions based on data. c. Descriptive statistics are more computationally sophisticated than inferential statistics. d. None of these are correct.

b. Descriptive statistics attempts to describe data, while inferential statistics attempts to make predictions based on data.

What type of statistics consists of the collection, organization, summarization, and presentation of data? a. Inferential statistics. b. Descriptive statistics. c. Either inferential statistics or descriptive statistics. d. Neither inferential statistics nor descriptive statistics.

b. Descriptive statistics.

You are the manager of a restaurant that delivers pizza to college dormitory rooms. You have just changed your delivery process to reduce the mean time between the order and completion of delivery from the current 25 minutes. A sample of 36 orders using the new delivery process yields a mean of 22.4 minutes. Assume the population standard deviation of completion of delivery is 5 minutes, is there evidence that the population mean delivery time has been reduced from the previous population mean value of 25 minutes? 21. What would be the proper set of hypotheses? a. H0: µ = 25; H1 : µ ≠ 25 b. H0 : µ ≥ 25; H1 : µ < 25 c. H0: π ≥ 25; H1 : π < 25 d. H0: µ ≤ 25; H1 : µ > 25

b. H0 : µ ≥ 25; H1 : µ < 25

Among the sampled 100 CFA members, 70 reported that the lack of ethical culture within financial firms had contributed the most to the lack of trust in the financial industry. Based on this information, you wish to determine if the population proportion of members indicating that lack of ethical culture within financial firms has contributed the most to the lack of trust in the financial industry is different from the CFA's reported 64%. Which of the following would be the proper hypotheses for testing this? a. H0 : π ≥ .64, H1 : π < .64 b. H0 : π = .64, H1 : π ≠.64 c. H0 : π =0.70, H1 : π ≠ 0.70 d. H0 : μ = 70, H1 : μ ≠ 70

b. H0 : π = .64, H1 : π ≠.64

A histogram that is positively skewed a. Is symmetric b. Has a longer upper tail than lower tail c. Has a longer lower tail than upper tail d. None of these statements are correct

b. Has a longer upper tail than lower tail

Use the following scenario for the next seven questions. A production filling operation has a historical standard deviation of 6 ounces. When in perfect adjustment, the mean filling weight for the production process is 50 ounces. A quality control inspector periodically randomly selects 36 containers and uses the sample mean filling weight to see if the process is in perfect adjustment. He finds that the sample mean is 48.6 ounces. In this scenario, which of the following would be the proper hypotheses? a. Ho: μ= 50 H1: μ > 50 b. Ho: μ= 50 H1: μ ≠ 50 c. Ho: μ= 48.6 H1: μ > 48.6 d. H0: μ= 48.6 H1: μ ≠ 48.6

b. Ho: μ= 50 H1: μ ≠ 50

A simple random sample of 100 observations was drawn from a normal population. The mean and standard deviation of the sample were 120 and 25, respectively. To test the following hypotheses, with a = .10 Ho: μ = 125 H1: μ ≠ 125 Which of the following is correct? a. Reject H0 at the 10% level of significance but Do Not reject H0 at the 5% level of significance b. Reject H0 at the 10% level of significance and Reject H0 at the 5% level of significance c. Do Not Reject H0 at the 10% level of significance but Reject H0 at the 5% level of significance d. Do Not Reject H0 at the 10% level of significance and Do Not Reject H0 at the 5% level of significance

b. Reject H0 at the 10% level of significance and Reject H0 at the 5% level of significance

A manager runs a store that serves about 250,000 customers. He wants to know some information about them, so he conducts a survey. One of the questions he asks for this survey is: "How many times per month do you shop for groceries at this store?" He surveys 300 of his customers as they leave his store over a period of three different days. The population of interest for the store manager is: a. The 300 customers in the survey b. The 250,000 customers c. The customers who came into his store during the 3 days of the survey d. The number of people who live in the city where his store is

b. The 250,000 customers

An auto analyst is conducting a satisfaction survey, sampling from a list of 10,000 new car buyers. The list includes 2,500 Ford buyers, 2,500 GM buyers, 2,500 Honda buyers, and 2,500 Toyota buyers. The analyst selects a sample of 400 car buyers, by randomly sampling 100 buyers of each brand. Is this an example of a probability sample? a. No, because each buyer in the sample was randomly sampled. b. Yes, because each buyer had an equal chance of being sampled. c. Yes, because car buyers of every brand were equally represented in the sample. d. No, because every possible 400-buyer sample did not have an equal chance of being chosen.

b. Yes, because each buyer had an equal chance of being sampled.

Paul and Sharon Jones, co-owners of a shopping mall, are interested in studying the purchasing patterns of their shoppers. They measure how long shoppers are in the mall and how much money they spend per hour. Based on a sample of 60 shoppers, they find that the shoppers spend, on average, $54 per hour of shopping with a standard deviation of $21. Calculate a 95% confidence interval for the population mean of the amount of money shoppers spend per hour on shopping. a. [48.89, 59.11] b. [48.58, 59.42] c. [49.47, 58.53] d. [49.55, 58.45]

b. [48.58, 59.42]

To investigate the correct hypothesis, what is the p-value of the test statistic? a. about 0.1 b. about 0.2 c. about 0.6 d. about 0.8

b. about 0.2

The major problem with battery powered cars is the limited time they can be driven before the batteries must be recharged. StuckPedal Motors has developed a battery pack that will power a car at a sustained speed of 45 miles per hour for an average of 8 hours with a standard deviation of 0.4 hours. What is the likelihood that a randomly chosen car equipped with the StuckPedal battery pack will be able to travel at 45 miles per hour for more than 8.4 hours? a. less than 1% b. about 16% c. about 34 % d. about 99%

b. about 16%

b. t = 1.318

For a sample of size 25 taken from a normally distributed population, if the population standard deviation (σ) is not given, then you would need to use which of the following to construct a 99% confidence interval for the population mean: a. t = 2.4922 b. t = 2.7969 c. Z = 2.575 d. Z = 2.33

b. t = 2.7969

Many Happy Returns is a tax preparation service with offices throughout the western United States. The manager believes the average number of returns processed by employees of Many Happy Returns during tax season is about 12 per day. He recruits 36 employees who volunteer to complete a survey during tax season. This survey revealed the following sample descriptive of returns processed daily. Mean = 12.50 Standard Error = 0.42 Median = 13 Mode = 13 Standard Deviation = 2.50 Sample Variance = 6.26 Range = 9 Min = 8 Max = 17 Sum = 450 Count = 36 In the scenario above, what is the population parameter of interest? a. the average tax returns processed by the 36 employees sampled b. the average tax returns processed by all the employees in Many Happy Returns c. the 36 employees d. the number of employees in Many Happy Returns

b. the average tax returns processed by all the employees in Many Happy Returns

The U of A Student Volunteer Association is interested in students' travel plans for Spring Break. They conduct a survey of 50 randomly selected students and asks them about their vacation plans. 38 students stated they would not take a vacation. Estimate with 90% confidence the actual proportion of students who are planning take a vacation over Spring Break. a. 0.10 ± 0.099 b. 0.10 ± 0.233 c. 0.24 ± 0.099 d. 0.24 ± 0.233

c. 0.24 ± 0.099

The incomes of Canadian residents are normally distributed with a mean of $40,000 and a standard deviation of $6,000. What is the probability that average income of 25 randomly selected Canadians will be less than $40,000? a. 0.0095 b. 0.2500 c. 0.5000 d. 0.9500

c. 0.5000

The incomes of Canadian residents are normally distributed with a mean of $40,000 and a standard deviation of $6,000. What is the probability that the average income of 25 randomly selected Canadians will be more than $40,000? a. 0.0095 b. 0.2500 c. 0.5000 d. 0.9500

c. 0.5000

The mileage (i.e., miles per gallon) of a brand of hybrid automobiles is a normally distributed variable with a mean (µ) of 60 and a standard deviation (σ) of 3. Suppose that 10 automobiles are chosen at random. What is the probability that the average mileage of these 10 automobiles would be between 59 and 61? a. 0.2661 b. 0.3531 c. 0.7082 d. 0.9993

c. 0.7082

Obsolete Video, a movie rental store, is debating increasing the fee it charges customers for late returns. A review of the customer account database reveals that the number of late charges per year is normally distributed, with a mean of 3.6 late fees and a standard deviation of 1.2 late fees. If 10 customer accounts were randomly selected, what is the probability that their average number of late fees falls between 3 and 4? a. 0.3220 b. 0.6470 c. 0.7972 d. 0.9630

c. 0.7972

Automatic banking machine (ABM) customers can perform several transactions quickly and efficiently. A banking consultant has noted that the times to complete a transaction are normally distributed with a mean of 34 seconds and a standard deviation of 4 seconds. Suppose 6 banking customers are chosen at random. What is the probability that the average time of these 6 customers is between 32 and 37 seconds? a. 0.4648 b. 0.5783 c. 0.8566 d. 0.9999

c. 0.8566

...Of course, Nordstrom is not willing to give away such information to a competitor, so she goes into various departments in a Nordstrom store and measures how many seconds it takes before a salesperson greets her. She obtains 49 such measurements and records them in an Excel spreadsheet. She calculated the sample mean and found it to be 19.39. Assume that she knows the population standard deviation is 14 seconds. 1. Which of the following would be used to calculate the 95% LCL? a. 19.39 - (1.96 * .29) b. 19.39 - (1.96 * 14) c. 19.39 - (1.96 * 2) d. 19.39 - (2.01 * .29) In the above problem, if the population standard deviation was 28 seconds, how would the results be affected? a. The confidence interval estimate would be wider. b. The point estimate of the population mean would be smaller. c. The point estimate of the population mean would be larger. d. The confidence interval estimate would be narrower.

c. 19.39 - (1.96 * 2) a. The confidence interval estimate would be wider.

A manager wanted to know the average number of sodas that U of A students purchase on campus during a month, so he surveys a random sample of 49 students and has them keep track of how many cans they buy for a month. He used these data to calculate both 90% and 95% confidence interval estimates of the mean and these are displayed below in no order. t-Estimate: Mean Mean - 29.1382 Standard Deviation - 4.6218 LCL - 28.03069 UCL - 30.24563 LCL - 27.81054 UCL - 30.46578 Which of the following is the 95% LCL for the mean number of cans of soda purchased? a. 28.03069 b. 30.46578 c. 27.81054 d. 30.24563 To construct a 98% confidence interval, what value of Z do you use? a. 2.05 b. 2.33 c. 1.96 d. 2.58

c. 27.81054 b. 2.33

Professor Adams knows that in the past, the average amount of time spent preparing for the data analysis final was 8.5 hours with a standard deviation of 2.0 hours. He would like to estimate the amount of time his students spent preparing last semester so he asks a sample of 15 students how many hours they prepared for the final and found an average of 7.9 hours. Estimate the amount of time Prof Adams' students spent preparing for the final using a 90% confidence interval. a. 4.61 to 11.19 hours b. 6.79 to 9.01 hours c. 7.05 to 8.75 hours d. 7.65 to 9.35 hours How would the results be different if you used a 95% confidence interval? a. The interval would be smaller. b. The interval would be wider. c. The interval would be about the same due to the small sample size. d. Not enough information provided to answer the question.

c. 7.05 to 8.75 hours b. The interval would be wider.

A manager runs a store that serves about 250,000 customers. He wants some information about them, so he conducts a survey. One of the questions he asks for this survey is: Which of the following is the most important reason for buying your groceries at this store? (Choose one) ___ meat quality ___ low prices ____ produce quality ____ quality of service Which is the preferred way to display the data from this question? a. A time series graph b. A scatter diagram c. A pie chart d. A histogram

c. A pie chart

Suppose we took random samples of size 100 from a strongly right-skewed distributed population; the shape of the sampling distribution would be: a. Skewed to the left b. Skewed to the right c. Approximately normal d. Unknown; we don't have enough information to determine the shape

c. Approximately normal

(realtes to previous questions) After conducting the appropriate statistical test, what can you conclude about the correct hypothesis? a. Fail to reject the null hypothesis at the .01 significance level b. Fail to reject the null hypothesis at the .05 significance level c. Both a and b d. None of above

c. Both a and b

(relates to previous question) Based on the test result, what is the correct decision? a. Reject the null hypothesis at the .05 significance level b. Reject the null hypothesis at the .01 significance level c. Both a and b d. Do not reject the null hypothesis

c. Both a and b

Which of the following statements is true? a. Nonprobability samples MAY represent the population of interest. b. Probability samples MAY represent the populations of interest. c. Both statements are true. d. Neither statement is true.

c. Both statements are true.

Which of the following IS NOT a probability sampling method? a. Simple Random b. Cluster Sample c. Convivence Sample d. Stratified Sample

c. Convivence Sample

A production filling operation has a historical standard deviation of 6 ounces. When in perfect adjustment, the mean filling weight for the production process is 50 ounces. A quality control inspector periodically randomly selects 36 containers and uses the sample mean filling weight to see if the process is in perfect adjustment. He finds that the sample mean is 48.6 ounces. Using a 5% level of significance, what would be the correct decision and conclusion in this case? a. Reject the null hypothesis and conclude that the machine is in perfect adjustment. b. Reject the null hypothesis and conclude that the machine is not in perfect adjustment. c. Do not reject the null hypothesis and conclude that the machine is in perfect adjustment. Do not reject the null hypothesis and conclude that the machine is not in perfect adjustment

c. Do not reject the null hypothesis and conclude that the machine is in perfect adjustment.

Based on this test, the correct decision would be a. Reject the null hypothesis and conclude that the number of returns processed by employees of Many Happy Returns is not different from 12 per day as expected by the manager at α=.01 b. Reject the null hypothesis and conclude that the number of returns processed by employees of Many Happy Returns differs from 12 per day as expected by the manager at α=.01 c. Fail to reject the null hypothesis and conclude that the number of returns processed by employees of Many Happy Returns is not different from 12 per day as expected by the manager at α=.01 d. Fail to reject the null hypothesis and conclude that the number of returns processed by employees of Many Happy Returns differs from 12 per day as expected by the manager at α=.01

c. Fail to reject the null hypothesis and conclude that the number of returns processed by employees of Many Happy Returns is not different from 12 per day as expected by the manager at α=.01

Based on your test of the hypothesis stated in Question (92), what should be the correct statistical decision (α=.01)? a. Reject the null hypothesis and state that the population proportion of members indicating that lack of ethical culture within financial firms has contributed the most to the lack of trust in the financial industry is different from the CFA's reported 64% at α=.01 b. Reject the alternative hypothesis the population proportion of members indicating that lack of ethical culture within financial firms has contributed the most to the lack of trust in the financial industry is NOT different from the CFA's reported 64% at α=.01 c. Fail to reject the null hypothesis the population proportion of members indicating that lack of ethical culture within financial firms has contributed the most to the lack of trust in the financial industry is NOT different from the CFA's reported 64% at α=.01 d. Fail to reject the alternative hypothesis the population proportion of members indicating that lack of ethical culture within financial firms has contributed the most to the lack of trust in the financial industry is different from the CFA's reported 64% at α=.01

c. Fail to reject the null hypothesis the population proportion of members indicating that lack of ethical culture within financial firms has contributed the most to the lack of trust in the financial industry is NOT different from the CFA's reported 64% at α=.01

A histogram that is negatively skewed a. Is symmetric b. Has a longer upper tail than lower tail c. Has a longer lower tail than upper tail d. None of these statements are correct

c. Has a longer lower tail than upper tail

c. It would get narrower

A manager of a recording company wants to know if UA students are typical of other college students in terms of whether they will subscribe to a music service for $7.99 per month. Nationally, he knows that 12% will do so. He randomly samples 400 UA students and asks them if they would subscribe for $7.99 monthly. He codes their responses (1=yes, 2=no). What type of data is used in this scenario? a. Ratio b. Interval c. Nominal d. Ordinal

c. Nominal

A clothing outlet store in Illinois reviews its inventory and uses the following variables: 1. T-shirt selling price, 2. T-shirt colors, 3. Outlet Location (Chicago, Rockford, Lake Forest, East St. Louis, Quincy) and 4. Total number of employees. The data collected in 1, 2, 3, and 4 above are: a. Nominal, ratio, nominal, ratio b. Ratio, nominal, nominal, ordinal c. Ratio, nominal, nominal, ratio d. Ordinal, nominal, nominal, ratio

c. Ratio, nominal, nominal, ratio

In your job as a market analyst for the Bank of Fayetteville, a review of your records shows a positive relationship between household income and debt. What is the best way to graph this information? a. Pie chart b. Ogive c. Scatter diagram d. Histogram

c. Scatter diagram

A researcher at a local elementary school wants to assess reading achievement of third graders. She puts together a list of all the third graders. Then, she randomly selects a student from the first three students on the list. Starting with that student, she selects every third student for the assessment. For example, if student number 2 were the first student selected, the sample would consist of students' number 2, 5, 8, 11, 14, etc. What type of sample is this? a. Convenience Sample b. Custer Sample c. Systematic Sample d. Stratified Sample

c. Systematic Sample

If 400 packages were randomly selected, how would the distribution of mean package weights compare to the distribution in the previous question? a. The mean would get larger. b. The mean would get smaller. c. The standard error would decrease. d. The standard error would increase.

c. The standard error would decrease.

For a sample size of 25 taken from a normally distributed population with population standard deviation (σ) equal to 5, a 99% confidence interval for the population mean would require: a. t = 2.492 b. t = 2.797 c. Z = 2.575 d. Z = 2.33

c. Z = 2.575

A university is interested in uncovering what the mean GPA of its graduates from the Science and Engineering programs is. A random sample of 45 Science and Engineering students is taken and is found to have a mean GPA equal to 3.04. The standard deviation for all Science and Engineering students is assumed to be equal to .40. Calculate a 95% confidence interval of the population mean for Science and Engineering students (round to two decimal places when performing all calculations). a. [2.94, 3.14] b. [2.96, 3.12] c. [2.92, 3.16] d. [2.90, 3.18]

c. [2.92, 3.16]

A study of waiting times at fast-food restaurants conducted by The Morning News in October of 2006 showed that the average waiting time (µ) to get food after placing an order at McDonald's, Burger King, and Wendy's was 85 seconds. Assume that waiting times are normally distributed and that the standard deviation (σ) equals 20 seconds. If you took a random sample of 5 customers from a fast-food restaurant, what is the probability that their mean wait time was greater than 93 seconds? a. about 2% b. about 4% c. about 19% about 34%

c. about 19%

What sampling method was used: a. stratified b. simple random c. convenience d. no sampling method was used

c. convenience

I ask the students in my Data Analysis class to record the number of hours spent on Facebook the week before Exam 1 and compare this to their exam scores. The results show that more time on Facebook is related to lower exam scores. If I wanted to draw a graph to display the results, I should use a(n): a. ogive b. histogram c. scatter diagram d. bar chart

c. scatter diagram

Mifrin, the manufacturer of an over-the-counter pain reliever, claims that its product brings relief to headache sufferers in less than 3.5 minutes, on average. To make this claim in its commercials, Mifrin was required to show evidence that headache relief really did come in less than 3.5 minutes, on average. Mifrin reported that for a random sample of 50 headache sufferers, the mean time to relief was 3.3 minutes and the standard deviation was 60 seconds. You would like to estimate the average time it takes for headache sufferers to feel relief after taking Mifrin. Which of the following would you use to calculate the 99% confidence interval? a. z = ±2.300 b. z = ±2.575 c. t = ±2.678 d. t = ±2.403

c. t = ±2.678

Mean = 12.50 Standard Error = 0.42 Median = 13 Mode = 13 Standard Deviation = 2.50 Sample Variance = 6.26 Range = 9 Min = 8 Max = 17 Sum = 450 Count = 36 What is the actual value of the test statistic that you would need to use to test the correct hypothesis? a. -1.19 b. -0.2 c. +0.2 d. +1.19

d. +1.19

Joseph Foreman is the Chief Marketing Officer (CMO) of a major investment firm and is looking to provide several new investment opportunities to his customers. Since this will be a major project for his firm, he wants to be sure that at least 70% or more of his customers will be interested in buying. He presents the investments to a random sample of 150 of his customers and determines whether they would be interested in buying. He coded their response as either 1 = "likely to buy" or 0 = "unlikely to buy." 117 customers indicated they would be interested in buying, 33 said they would not. Estimate with 95% confidence the proportion of customers that will be interested in buying (round to three digits when calculating your answer): a. .70 ± .0733 b. .70 ± .0663 c. .78 ± .0733 d. .78 ± .0663

d. .78 ± .0663

d. 0.16

The mileage (i.e., miles per gallon) of a brand of hybrid automobiles is a normally distributed variable with a mean (µ) of 60 and a standard deviation (σ) of 3. Suppose that 10 automobiles are chosen at random. What is the probability that the mean mileage of these automobiles will be at least 59? a. 0.0000 b. 0.3531 c. 0.6305 d. 0.8541

d. 0.8541

Obsolete Video, a movie rental store, is debating increasing the fee it charges customers for late returns. A review of the customer account database reveals that the number of late charges per year is normally distributed, with a mean of 3.6 late fees and a standard deviation of 1.2 late fees. If 30 customer accounts were randomly selected, what is the probability that their average number of late fees falls between 3 and 4? a. 0.3220 b. 0.6470 c. 0.7972 d. 0.9630

d. 0.9630

Automatic banking machine (ABM) customers can perform several transactions quickly and efficiently. A banking consultant has noted that the times to complete a transaction are normally distributed with a mean of 34 seconds and a standard deviation of 4 seconds. Suppose 16 banking customers are chosen at random. What is the probability that the average time of these 16 customers is between 32 and 37 seconds? a. 0.4648 b. 0.5783 c. 0.8566 d. 0.9759

d. 0.9759

Automatic banking machine (ABM) customers can perform several transactions quickly and efficiently. A banking consultant has noted that the times to complete a transaction are normally distributed with a mean of 34 seconds and a standard deviation of 4 seconds. Suppose 16 banking customers are chosen at random. What is the probability that the time to complete a transaction for a randomly selected customer is between 32 and 37 seconds? a. 0.4648 b. 0.5783 c. 0.8566 d. 0.9759

d. 0.9759

Mean = 12.50 Standard Error = 0.42 Median = 13 Mode = 13 Standard Deviation = 2.50 Sample Variance = 6.26 Range = 9 Min = 8 Max = 17 Sum = 450 Count = 36 Which of the following would be the 95% confidence interval estimate for the number of returns processed by all employees of Many Happy Returns? a. 12 ± 1.96×0.42 b. 12 ± 2.03×0.42 c. 12.5 ± 1.96×0.42 d. 12.5 ± 2.03×0.42

d. 12.5 ± 2.03×0.42

A manager runs a store that serves about 250,000 customers. He wants to know some information about them, so he conducts a survey. One of the questions he asks for this survey is: "How many times per month do you shop for groceries at this store?" The type of variable that he is measuring is: a. A nominal variable b. An ordinal variable c. A standard normal variable d. A ratio variable

d. A ratio variable

Which of the following is a measure of dispersion? a. Mean b. Standard Deviation c. Mode d. All of these are measures of dispersion

d. All of these are measures of dispersion

Why would one study statistics? a. To be an informed consumer of information. b. To make sense of the information that you receive. c. To make data-driven decisions d. All of these are reasons to study statistics

d. All of these are reasons to study statistics

Fayetteville AutoPark has decided to use a customer satisfaction survey to learn more information about people who have recently purchased cars from them. From existing records, management knows that the distribution of the amount spent per customer has an extreme positive skew with a mean of $17,000. If 100 people responded to the survey, what would be the shape of the sampling distribution? a. Approximately u-shaped b. Negatively Skewed c. Positively Skewed d. Approximately normally distributed (bell shaped curve)

d. Approximately normally distributed (bell shaped curve)

Mean = 12.50 Standard Error = 0.42 Median = 13 Mode = 13 Standard Deviation = 2.50 Sample Variance = 6.26 Range = 9 Min = 8 Max = 17 Sum = 450 Count = 36 What would be the appropriate hypothesis if you were to conduct a hypothesis test to determine if the average returns processed by employees of Many Happy Returns is different from 12 per day as expected by the manager? a. H0 : π ≥ 12, H1 : π < 12 b. H0 : μ ≥ 12, H1 : μ < 12 c. H0 : π = 12, H1 : π ≠ 12 d. H0 : μ = 12, H1 : μ ≠ 12

d. H0 : μ = 12, H1 : μ ≠ 12

Use the following scenario to answer the next five questions. A researcher at the University of Michigan medical school believes coffee consumption may increase heart rate. Suppose it is known that heart rate is normally distributed with an average of 70 beats per minute for adults. A random sample of 25 adults was selected, and it was found that their average heart rate was 73 after coffee consumption, with a standard deviation of 7. 1. What is the proper set of hypotheses? a. Ho: μ = 70 H1: μ > 73 b. Ho: μ = 73 H1: μ < 73 c. Ho: μ = 70 H1: μ < 70 d. Ho: μ = 70 H1: μ > 70

d. Ho: μ = 70 H1: μ > 70

Which of the following statements is true? a. Nonprobability samples NEVER represent the population of interest. b. Probability samples ALWAYS represent the populations of interest. c. Both statements are true. d. Neither statement is true.

d. Neither statement is true.

Fayetteville AutoPark has decided to use a customer satisfaction survey to learn more information about people who have recently purchased cars from them. From existing records, management knows that the distribution of the amount spent per customer has an extreme positive skew with a mean of $17,000. Customers were asked to indicate the type of car that they drive. This represents what type of data? a. Ratio b. Interval c. Ordinal d. Nominal

d. Nominal

d. Ratio

A researcher at the University of Michigan medical school believes coffee consumption may increase heart rate. Suppose it is known that heart rate is normally distributed with an average of 70 beats per minute for adults. A random sample of 25 adults was selected, and it was found that their average heart rate was 73 after coffee consumption, with a standard deviation of 7. What is the correct decision and conclusion in this case? a. Do not reject the null hypothesis and conclude heart rate does not increase with caffeine consumption. b. Do not reject the null hypothesis and conclude heart rate does increase with caffeine consumption. c. Reject the null hypothesis and conclude heart rate does not increase with caffeine consumption. d. Reject the null hypothesis and conclude heart rate does increase with caffeine consumption.

d. Reject the null hypothesis and conclude heart rate does increase with caffeine consumption.

A researcher at a local elementary school wants to assess reading achievement of third graders. She puts together a list of all the third graders. She divides the list into boys and girls, then she randomly selects students from each list. What type of sample is this? a. Convenience Sample b. Custer Sample c. Systematic Sample d. Stratified Sample

d. Stratified Sample

Compute the mode of the following data: 5 3 4 a. 3 b. 4 c. 5 d. The data does not have a mode

d. The data does not have a mode

A manager of a recording company wants to know if UA students are typical of other college students in terms of whether they will subscribe to a music service for $7.99 per month. Nationally, he knows that 12% will do so. He randomly samples 400 UA students and asks them if they would subscribe for $7.99 monthly. He codes their responses (1=yes, 2=no). What is the correct decision? a. Reject Ho at the .10 significance level. b. Reject Ho at the .05 significance level. c. Both a and b are correct. d. There is not enough information to decide.

d. There is not enough information to decide.

Which of the following statements about sampling is true? a. Using nonprobability sampling means you CAN generalize beyond the sample. b. Using probability sampling means you CANNOT generalize beyond the sample. c. Using nonprobability sampling or probability sampling means you CAN generalize beyond the sample. d. Using probability sampling means you CAN generalize beyond the sample.

d. Using probability sampling means you CAN generalize beyond the sample.

You are interested in the amount of money that college students spend each semester on books. From previous research, you know that the population distribution for money spent on books is positively skewed. If you created the sampling distribution of the mean for n = 50 students, how would you describe its shape? a. approximately binomial b. uniform distribution c. negatively skewed d. approximately bell-shaped

d. approximately bell-shaped

The dean of the Walton College was interested in the attendance rates at classes throughout the college, so he visited a random sample of 25 classes (13 on a Wednesday and 12 on a Thursday). In each class he asked the instructor what percentage of the students were in attendance that day. Attendance at these 25 classes ranged from 67% to 100%. If he wanted to estimate the attendance for all Walton College classes based on these data what should he do? a. Construct a confidence interval estimate of the population mean b. Construct a confidence interval estimate of the population proportion c. Use the sample proportion as a point estimate of the population proportion d. b and c

d. b and c

A dealer in New Jersey has surveyed the cars on his lot and has recorded a dataset with the following variables: 1. Make/ Model, 2. Miles per Gallon, 3. Car Type (e.g., economy, full size), 4. Price, and 5. Color, The data collected for above variables 1, 2, 3, 4, and 5 are: a. nominal, ordinal, nominal, ratio, nominal b. ordinal, ratio, ordinal, ordinal, ordinal c. ordinal, ratio, ordinal, ratio, nominal d. nominal, ratio, nominal, ratio, nominal

d. nominal, ratio, nominal, ratio, nominal

In a recent survey of its graduating seniors, the Walton College of Business gathered data for several variables, including the following: (1) Whether or not the student had a part time job (1=yes, 2=no) (2) The number of math courses they had taken (3) Academic major (Accounting, Finance, Information Systems, Economics, Management, Marketing) (4) Amount of student loans outstanding (dollars) (5) Home state (Arkansas, Texas, Missouri, Oklahoma, other) The data described in 1 -5 above are: a. nominal, ordinal, nominal, ratio, ratio b. nominal, ratio, ordinal, ratio, ordinal c. nominal, ordinal, nominal, ratio, nominal d. nominal, ratio, nominal, ratio, nominal

d. nominal, ratio, nominal, ratio, nominal

You are the manager of a restaurant that delivers pizza to college dormitory rooms. You have just changed your delivery process to reduce the mean time between the order and completion of delivery from the current 25 minutes. A sample of 36 orders using the new delivery process yields a mean of 22.4 minutes. Assume the population standard deviation of completion of delivery is 5 minutes, is there evidence that the population mean delivery time has been reduced from the previous population mean value of 25 minutes? What type of data is used in this scenario? a. nominal b. ordinal c. interval d. ratio

d. ratio

d. t = 2.143

Use the following scenario to answer the next three questions. A simple random sample of 100 observations was drawn from a normal population. The mean and standard deviation of the sample were 120 and 25, respectively. To test the following hypotheses, with a = .10 Ho: μ = 125 H1: μ ≠ 125 Which of the following are the correct critical values of the test statistic? a. z = ± 1.96 b. z = ± 1.645 c. t = ± 1.29 d. t = ± 1.66

d. t = ± 1.66

d. z = -1.40

For a sample of size 41 taken from a normally distributed population with standard deviation (σ) equal to 5, a 99% confidence interval for the population mean would require the use of: a. z = 1.645 b. t = 1.328 c. t = 1.729 d. z = 2.575

d. z = 2.575

A simple random sample of 100 observations was drawn from a normal population. The mean and standard deviation of the sample were 120 and 25, respectively. To test the following hypotheses, with a = .10 Ho: μ = 125 H1: μ ≠ 125 a. Bar Chart (Vertical Bars) b. Scatter Plot c. Bar Chart (Horizontal bars) d. Pie Chart e. Histogram f. Line Chart

WCOB Data Analysis Units 1-4 Review Aguiar

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