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A government agency was charged by the legislature with estimating the length of time it takes citizens to fill out various forms. The agency generated an 85% confidence interval, a 90% confidence interval, and a 99% confidence interval, all of which are listed below. Which one is the 85% confidence interval?

(12.63, 12.97)

In a survey of 1000 people, 700 people said that they voted in the last presidential election. Let p denote the proportion of all people who voted. Which equation should he use to construct the 95% confidence interval for the true proportion of all people who voted?

(p-za/2*sqrt(pq/n)

A voter wants to know how much time governors spend on golf courses per year. He finds data on 12 governors. The sample average is 48 days with standard deviation 10 days. Assume the population amount of time is not normally distributed. What equation should he use to make a confidence interval for the population mean time?

(x-ta, x+ta)

The probability distribution of a discrete random variable X is given by (p, 0.34, 0.16, 0.10, 0.02) Find the value of p, the missing probability in the table.

0.38

The probability distribution of a discrete random variable X is shown in the following table: (0.24, 0.20, 0.37, 0.05, 0.14) Find P (X greater than or = to 2)

0.76

Which of the following statements are true about the sampling distribution of x? 1. The mean of the sampling distribution is equal to the mean of the population. 2. The standard deviation of the sampling distribution is equal to the standard deviation of the population. 3. The shape of the sampling distribution is always approximately normal.

1 only

Cell phone bills for a city's residents have a mean of $64 and a standard deviation of $14. Random samples of 100 bills are drawn from this population, and the mean of each sample is found. What is the standard deviation for the sampling distribution of x, i.e., ax?

1.4

If A = {3, 6, 9, 10} and B = {3, 4, 5, 6}, what is A ∪ B?

3, 4, 5, 6, 9, 10

If A = {3, 6, 9, 10} and B = {3, 4, 5, 6}, what is A ∩ B?

3,6

A company conducts a survey of 1000 randomly selected individuals to get their overall impressions of the past year. Results are shown below. What is the probability that the next person surveyed has a positive impression?

410/1000 = 0.41

A university dean wants to know how many credits students are taking. They randomly sample some students and put the results in the histogram below. How many students from the sample are taking between 3 and 9 credits?

5

Cell phone bills for a city's residents have a mean of $64 and a standard deviation of $14. Random samples of 100 bills are drawn from this population, and the mean of each sample is found. What is the mean of the sampling distribution?

64

A dog groomer wants to evaluate if she should expand her business to a new city. She randomly selects 20 people in the city and asks them how many dogs they have. She put her results on the table below: How would she calculate the MEAN number of dogs per person in the city?

= 0x.030 + 1x0.50 + 2x0.10 + 3x0.10

A veterinarian reads that 15% of dogs are allergic to chicken. However, he claims that the actual proportion is less than his. He randomly selects 15 of his customers and asks them if their dog is allergic to chicken. 3 of them say yes. Assume the population is normally distributed and use a = 0.01. which function in Excel finds the test statistic?

=(0.20-0.15)/SQRT(0.15*0.85/15)

A nutritionist claims that the average amount of sugar in a 16 oz soda is at least 54 g. He randomly samples 13 sodas and finds they contain an average of 50 g of sugar with a standard deviation of 4 g. Assume the population is normally distributed and use a=0.10 to test the claim. Which function in Excel finds the test statistic?

=(50-54)/(4/SQRT(13))

A zookeeper takes a sample of 50 penguins and finds their average weight to be 51 lb with a standard deviation of 4 lb. How would you find a z-score corresponding to a penguin that weighs 52 lb in Excel?

=(52-51)/4

A diabetic claims that the average cost of insulin per year for a Type 1 diabetic is $5,605. She takes a sample of 100 Type 1 diabetics and finds their average cost is $5,750 with a standard deviation of $370. Use 𝛼=0.05 to test the claim. Which function in Excel finds the test statistic?

=(5750-5605)/(370/SQRT(100))

A survey shows that people use cell phones an average of 1.6 years with a standard deviation of 0.3 years. A user is randomly selected. If cell phone use in normally distributed, we can use Excel to calculate the probability that the randomly selected user uses their phone for MORE than 1 year with the function:

=1-NORM.DIST(1, 1.6, 0.3, TRUE)

A sociologist wishes to test Ho: u less than or = 42 vs. Ha: u greater than 42. The sociologist takes a sample size 10 and calculates a standardized test statistic of 2.34. To calculate a p-value for the test in Excel, the sociologist should use:

=1-T.DIST(2.34, 9, TRUE)

How would you find the mean of data in the range B1 to B6 in Excel?

=AVERAGE(B1:B6)

A survey shows that people use cell phones an average of 1.6 years with a standard deviation of 0.3 years. A user is randomly selected. If cell phone use in normally distributed, we can use Excel to calculate the probability that the randomly selected user uses their phone for LESS than 1 year with the function:

=NORM.DIST(1, 1.6, 0.3, TRUE)

An ornithologist wants to know the probability that a randomly selected male kakapo (owl parrot) is between 3 and 7 lb. A sample of 39 males showed their mean weight is 4.5 lb with a standard deviation of 2 lb. What function gives this probability?

=NORM.DIST(7,4.5,2,TRUE) - NORM.DIST(3,4.5,2,TRUE)

To calculate Za/2 in Excel, use the function

=NORM.INV(1-alpha/2, 0, 1)

Using Excel, how would you find the standard deviation for a sample of data located in cells A1 to A10?

=STDEV.S(A1:A10)

A nutritionist claims that the average amount of sugar in a 16 oz soda is at least 54 g. He randomly samples 13 sodas. Assume the population is normally distributed and suppose the test statistic is -1.19. Which function in Excel find the p-value?

=T.DIST(-1.19, 12, TRUE)

A randomly selected sample size of 17 is taken. Assume the population is normally distributed. Which function finds the probability that t is less than 1.4?

=T.DIST(1.4, 16, TRUE)

A voter wants to know how much time governors spend on golf courses per year. He finds data on 12 governors. The sample average is 48 days with standard deviation 10 days. Assume the population amount of time is not normally distributed. Which of the following the critical value if he wants to build a range that is 90% likely to contain the true population average?

=T.INV(1-0.10/2, 11)

The score made by a particular student on a national standardized exam is the 75th percentile. This means that

About 75% of all scored on the exam were lower than his.

A test is made of Ho: u = 20 versus Ha: u /= 20. Suppose the true value of u is 25, and Ho is rejected. Determine whether the outcome is a Type 1 error, a Type 2 error, or a correct decision.

Correct Decision

The target temperature for a hot beverage the moment it is dispensed from a vending machine is 169 degrees F. A consumer organization believes that a particular brand of machine dispenses beverages whose temperature exceeds 169 degrees F. In this scenario, a Type 1 error would be:

Deciding that the beverages exceed 169 degrees F when they don't.

A diabetic claims that the average cost of insulin per year for a Type 1 diabetic is $5,605. She takes a sample of 100 Type 1 diabetics. She also find calculates the p-value for the hypothesis test and find that the p=value is 0.0724. Using 𝛼=0.05, what is the decision?

Fail to reject, Ho

A type 1 error occurs when

Ho is rejected when it's true

A diabetic claims that the average cost of insulin per year for a Type 1 diabetic is $5,605. She takes a sample of 100 Type 1 diabetics and finds their average cost is $5,750 with a standard deviation of $370. Use 𝛼=0.05 to test the claim. What are the hypotheses?

Ho: u = 5605 (claim) Ha: u /= 5605

A standard painkiller is known to bring relief in 3.5 minutes on average (u). A new painkiller is hypothesized to bring faster relief to patients. A sample of 40 patients are given the new painkillers. The sample yields a mean of 2.8 minutes and a standard deviation of 1.1 minutes. Which of the following pairs of hypotheses are appropriate for this study?

Ho: u greater than or equal to 3.5; Ha: u less than 3.5

Seven bear tracks were found in the woods. Their length was measured in inches and recorded in the table below: If another bear track was found that was 8 in, what would happen to the mean?

It would decrease

Which of the following would NOT be an appropriate measure of central tendency when looking at incomes of a middle class neighborhood when one neighbor just sold their startup idea to google for $4 million?

Mean

The mean score on a standardized math exam is 77.2; the standard deviation is 9.5. Zack is told that the z-score of his exam score is 1.3. Is Zack's score above average or below average?

above average

The Department of Education wishes to estimate the proportion of all college students who have a job off-campus. It surveyed 1600 randomly selected students; 451 had such jobs. The population of interest to the Department of Education is:

all college students

Mean, median, and mode are all measures of the center of a data set, while variance and standard deviation measure the spread of a data set.

center; spread

The level of significance is

the maximum allowable probability of rejecting the null hypothesis when its true

The p-value is

the probability of obtaining a value as extreme or more extreme than the observed value by chance alone, assuming the null hypothesis is true.

Which of the following is NOT a property of the standard normal distribution?

uniform in shape

A researcher wishes to estimate the average amount spent per person by visitors to a museum. She takes a random sample of forty-five visitors and obtains an average of $26 per person. The population of interest is:

visitors to the museum

In a random sample of 100 adults, 27 say they are in favor of outlawing cigarettes. Let p be the proportion of all adults who are in favor of outlawing cigarettes. A researcher wishes to test the following hypotheses: Ho: p = 0.23; Ha: p /= 0.23. In this scenario, the appropriate test statistic is:

z = (p hat - po/sqrt (pq/n)

If you are constructing a 95% confidence interval for a sample size of 100, what critical value should you use?

z0.025