Statistics final exam study guide

B. 0.0606

Find the area under the standard normal curve between z = 1.5 and z = 2.5. A. 0.9816 B. 0.0606 C. 0.9332 D. 0.9938

D. 19.7

Find the sample standard deviation. 38, 85, 61, 64, 53, 39, 27, 74, 34 A. 345.3 B. 17.6 C. 310.8 D. 19.7

C. 0.84

Find the value of zα. z0.2 A. 0.58 B. -0.84 C. 0.84 D. 0.8

A. simple random

Identify the type of sampling used. A lobbyist for the oil industry assigns a number to each senator and then uses a computer to randomly generate ten numbers. The lobbyist contacts the senators corresponding to these numbers. What sampling technique was used? A. simple random B. convenience C. stratified D. systematic E. cluster

A. systematic

Identify the type of sampling used. A sample consists of every 45th worker from a group of 4000 workers. What sampling technique was used? A. systematic B. convenience C. cluster D. simple random E. stratified

A. cluster

Identify the type of sampling used. A travel industry researcher interviews all of the passengers on five randomly selected cruises. What sampling technique is used? A. cluster B. stratified C. systematic D. convenience E. simple random

B. cluster

Identify the type of sampling used. A travel industry researcher interviews all of the passengers on five randomly selected cruises. What sampling technique is used? A. simple random B. cluster C. stratified D. systematic E. convenience

E. cluster

Identify the type of sampling used. At a local technical school, five auto repair classes are randomly selected and all of the students from each class are interviewed. What sampling technique is used? A. systematic B. stratified C. simple random D. convenience E. cluster

A. systematic

Identify the type of sampling used. Every fifth adult entering an airport is checked for extra security screening. What sampling technique is used? A. systematic B. cluster C. convenience D. simple random E. stratified

B. a numerical measure of the outcome of a probability experiment.

Provide an appropriate response. A random variable is A. generated by a random number table. B. a numerical measure of the outcome of a probability experiment. C. a qualitative attribute of a population. D. the variable for which an algebraic equation is solved.

D. equal to one.

Provide an appropriate response. The sum of the probabilities of a discrete probability distribution must be A. greater than one. B. between zero and one. C. less than or equal to zero. D. equal to one.

B. 0.28

olve the problem. Two dice are rolled. What is the probability of having both faces the same (doubles) or a total of 4 or 10? Round to the nearest hundredth. A. 0.15 B. 0.28 C. 0.06 D. 0.33

A. quantitative

Classify the variable as qualitative or quantitative. the number of calls received at a company's help desk A. quantitative B. qualitative

A. quantitative

Classify the variable as qualitative or quantitative. the weights of cases loaded onto an airport conveyor belt A. quantitative B. qualitative

B. quantitative

Classify the variable as qualitative or quantitative. the weights of cases loaded onto an airport conveyor belt A. qualitative B. quantitative

B. 13

Compute the range for the set of data. 4, 4, 7, 1, 8, 14, 9, 7, 8 A. 15 B. 13 C. 14 D. 6.9

B. 13

Compute the range for the set of data. 4, 4, 7, 1, 8, 14, 9, 7, 8 A. 6.9 B. 13 C. 14 D. 15

D. a numerical measure of the outcome of a probability experiment.

Provide an appropriate response. A random variable is A. generated by a random number table. B. a qualitative attribute of a population. C. the variable for which an algebraic equation is solved. D. a numerical measure of the outcome of a probability experiment.

C. 0.4987

Provide an appropriate response. Find the area under the standard normal curve between z = 0 and z = 3. A. 0.9987 B. 0.4641 C. 0.4987 D. 0.0010

C. 0.9332

Provide an appropriate response. Find the area under the standard normal curve to the left of z = 1.5. A. 0.7612 B. 0.0668 C. 0.9332 D. 0.5199

A. 2.821

Provide an appropriate response. Find the critical t-value that corresponds to 99% confidence and n = 10. A. 2.821 B. 1.833 C. 2.262 D. 3.250

B. 0.2881

Provide an appropriate response. Furnace repair bills are normally distributed with a mean of 269 dollars and a standard deviation of 30 dollars. If 144 of these repair bills are randomly selected, find the probability that they have a mean cost between 269 dollars and 271 dollars. A. 0.2119 B. 0.2881 C. 0.5517 D. 0.7881

C. 0.9893

Provide an appropriate response. A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 470 seconds and a standard deviation of 60 seconds. Find the probability that a randomly selected boy in secondary school will take longer than 332 seconds to run the mile. A. 0.4893 B. 0.0107 C. 0.9893 D. 0.5107

C. 1.75

Determine the critical value zα/2 that corresponds to the given level of confidence. 92% A. 1.45 B. 0.82 C. 1.75 D. 1.41

A. ordinal

Determine the level of measurement of the variable. an evaluation received by a physics student (excellent, good, satisfactory, or poor). A. ordinal B. nominal C. interval D. ratio

B. ordinal

Determine the level of measurement of the variable. an officer's rank in the military A. ratio B. ordinal C. interval D. nominal

B. ordinal

Determine the level of measurement of the variable. the medal received (gold, silver, bronze) by an Olympic gymnast A. ratio B. ordinal C. interval D. nominal

B. ratio

Determine the level of measurement of the variable. weight of rice bought by a customer A. interval B. ratio C. ordinal D. nominal

B. cohort; Individuals are observed over a long period of time.

Determine what type of observational study is described. Explain. A researcher wanted to determine whether women with children are more likely to develop anxiety disorders than women without children. She selected a sample of 900 twenty-year old women and followed them for a twenty-year period. At the start of the study, none of the women had children. By the end of the study 53% of the women had at least one child. The level of anxiety of each participant was evaluated at the beginning and at the end of the study and the increase (or decrease) in anxiety was recorded. The researchers analyzed the results to determine whether there was an association between anxiety and having children. A. cross-sectional; Information is collected at a specific point in time. B. cohort; Individuals are observed over a long period of time. C. retrospective; Individuals are asked to look back in time.

B. cross-sectional; Information is collected at a specific point in time.

Determine what type of observational study is described. Explain. Researchers wanted to determine whether there was an association between high blood pressure and the suppression of emotions. The researchers looked at 1800 adults enrolled in a Health Initiative Observational Study. Each person was interviewed and asked about their response to emotions. In particular they were asked whether their tendency was to express or to hold in anger and other emotions. The degree of suppression of emotions was rated on a scale of 1 to 10. Each person's blood pressure was also measured. The researchers analyzed the results to determine whether there was an association between high blood pressure and the suppression of emotions. A. cohort; Individuals are observed over a long period of time. B. cross-sectional; Information is collected at a specific point in time. C. retrospective; Individuals are asked to look back in time.

A. discrete

Determine whether the quantitative variable is discrete or continuous. the number of goals scored in a hockey game A. discrete B. continuous

B. observational study

Determine whether the study depicts an observational study or an experiment. A pollster obtains a sample of students and asks them how they will vote on an upcoming referendum. A. experiment B. observational study

A. experiment

Determine whether the study depicts an observational study or an experiment. A scientist was studying the effects of a new fertilizer on crop yield. She randomly assigned half of the plots on a farm to group one and the remaining plots to group two. On the plots in group one, the new fertilizer was used for a year. On the plots in group two, the old fertilizer was used. At the end of the year the average crop yield for the plots in group one was compared with the average crop yield for the plots in group two. A. experiment B. observational study

A. parameter

Determine whether the underlined value is a parameter or a statistic. 51.4% of the residents of Idlington Garden City are female. A. parameter B. statistic

B. statistic

Determine whether the underlined value is a parameter or a statistic. In a survey conducted in the town of Atherton, 28% of adult respondents reported that they had been involved in at least one car accident in the past ten years. A. parameter B. statistic

A. statistic

Determine whether the underlined value is a parameter or a statistic. In a survey conducted in the town of Atherton, 28% of adult respondents reported that they had been involved in at least one car accident in the past ten years. A. statistic B. parameter

D. 1320

Provide an appropriate response. A club elects a president, vice-president, and secretary-treasurer. How many sets of officers are possible if there are 12 members and any member can be elected to each position? No person can hold more than one office. A. 440 B. 660 C. 11,880 D. 1320

C. 34

Provide an appropriate response. A doctor at a local hospital is interested in estimating the birth weight of infants. How large a sample must she select if she desires to be 98% confident that the true mean is within 2 ounces of the sample mean? The standard deviation of the birth weights is known to be 5 ounces. A. 5 B. 6 C. 34 D. 33

D. 0.966

Provide an appropriate response. A human gene carries a certain disease from the mother to the child with a probability rate of 57%. That is, there is a 57% chance that the child becomes infected with the disease. Suppose a female carrier of the gene has four children. Assume that the infections of the four children are independent of one another. Find the probability that at least one of the children get the disease from their mother. Round to the nearest thousandth. A. 0.034 B. 0.045 C. 0.181 D. 0.966

C. For every 1-inch increase in height, we expect the child's head circumfrence to increse by 0.1827 inches.

Provide an appropriate response. A pediatrician wants to determine the relation that exists between a child's height, x, and head circumfrence, y. She randomly selects 11 children from her practice, measures their heights and head circumfrences in inches, and performs linear regression analysis on the data and obtains the following regression line: y = 0.1827x +12.4932 Interpret the slope of the line. A. For every 1-inch increase in head cirucmfernce, we expect the child's height to increse by 0.1827 inches. B. For a child who is zero inches tall will have a head circumfrence of 12.4932 inches. C. For every 1-inch increase in height, we expect the child's head circumfrence to increse by 0.1827 inches. D. For every 1-inch increase in height, we expect the child's head circumfrence to increse by 12.4932 inches.

D. between 352 and 548 sec

Provide an appropriate response. A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 450 seconds and a standard deviation of 50 seconds. Between what times do we expect most (approximately 95%) of the boys to run the mile? A. between 0 and 532.28 sec B. between 355 and 545 sec C. between 367.75 and 532.28 sec D. between 352 and 548 sec

B. equal to one.

Provide an appropriate response. The sum of the probabilities of a discrete probability distribution must be A. between zero and one. B. equal to one. C. less than or equal to zero. D. greater than one.

B. all Florida residents

Provide an appropriate response. A recent study attempted to estimate the proportion of Florida residents who were willing to spend more tax dollars on protecting the Florida beaches from environmental disasters. Thirty-two hundred Florida residents were surveyed. Which of the following is the population used in the study? A. the 3200 Florida residents surveyed B. all Florida residents C. all Florida residents who lived along the beaches D. the Florida residents who were willing to spend more tax dollars on protecting the beaches from environmental disasters

D. a strong positive linear correlation.

Provide an appropriate response. A researcher determines that the linear correlation coefficient is 0.85 for a paired data set. This indicates that there is A. insufficient evidence to make any decision about the correlation of the data. B. no linear correlation but that there may be some other relationship. C. a strong negative linear correlation. D. a strong positive linear correlation.

D. 268

Provide an appropriate response. A researcher wishes to estimate the number of households with two computers. How large a sample is needed in order to be 98% confident that the sample proportion will not differ from the true proportion by more than 6%? A previous study indicates that the proportion of households with two computers is 23%. A. 6 B. 347 C. 189 D. 268

D. the observed value of y and the predicted value of y.

Provide an appropriate response. A residual is the difference between A. the observed value of x and the predicted value of y. B. the observed value of y and the predicted value of x. C. the observed value of x and the predicted value of x. D. the observed value of y and the predicted value of y.

D. z = 0.84

Provide an appropriate response. A severe drought affected several western states for 3 years. A Christmas tree farmer is worried about the drought's effect on the size of his trees. To decide whether the growth of the trees has been retarded, the farmer decides to take a sample of the heights of 25 trees and obtains the following results (recorded in inches): 60 57 62 69 46 54 64 60 59 58 75 51 49 67 65 44 58 55 48 62 63 73 52 55 50 The tree farmer feels the normal height of a tree that was unaffected by the drought would be 65 inches. Find the z-score for a tree that is 65 inches tall. A. z = 0.98 B. z = 0.77 C. z = 0.98 D. z = 0.84

A. The student scored better on the geography test.

Provide an appropriate response. A student scores 74 on a geography test and 249 on a mathematics test. The geography test has a mean of 80 and a standard deviation of 5. The mathematics test has a mean of 300 and a standard deviation of 34. If the data for both tests are normally distributed, on which test did the student score better relative to the other students in each class? A. The student scored better on the geography test. B. The student scored the same on both tests. C. The student scored better on the mathematics test.

B. 0.292

Provide an appropriate response. A survey of 250 households showed 73 owned at least one snow blower. Find a point estimate for p, the population proportion of households that own at least one snow blower. A. 0.412 B. 0.292 C. 0.226 D. 0.708

C. There is a weak positive linear correlation.

Provide an appropriate response. A traffic officer is compiling information about the relationship between the hour or the day and the speed over the limit at which the motorist is ticketed. He computes a correlation coefficient of 0.12. What does this tell the officer? A. There is insufficient evidence to make any conclusions about the relationship between the variables. B. There is a moderate negative linear correlation. C. There is a weak positive linear correlation. D. There is a moderate positive linear correlation.

D. lurking variable.

Provide an appropriate response. A variable that is related to either the response variable or the predictor variable or both, but which is excluded from the analysis is a A. discrete variable. B. qualitative variable. C. random variable. D. lurking variable.

C. Absences

Provide an appropriate response. An instructor wishes to determine if there is a relationship between the number of absences from his class and a student's final grade in the course. What is the predictor variable? A. Student's performance on the final examination B. The instructor's point scale for attendance C. Absences D. Final Grade

B. 0.9938

Provide an appropriate response. Assume that blood pressure readings are normally distributed with a mean of 122 and a standard deviation of 9.6. If 144 people are randomly selected, find the probability that their mean blood pressure will be less than 124. A. 0.0062 B. 0.9938 C. 0.8615 D. 0.9998

B. 0.9938

Provide an appropriate response. Assume that blood pressure readings are normally distributed with a mean of 122 and a standard deviation of 9.6. If 144 people are randomly selected, find the probability that their mean blood pressure will be less than 124. A. 0.0062 B. 0.9938 C. 0.9998 D. 0.8615

C. (2.51, 3.21)

Provide an appropriate response. Construct a 90% confidence interval for the population mean, μ. Assume the population has a normal distribution. A sample of 15 randomly selected math majors has a grade point average of 2.86 with a standard deviation of 0.78. A. (2.41, 3.42) B. (2.28, 3.66) C. (2.51, 3.21) D. (2.37, 3.56)

B. The value has no practical interpretation since a GMAT of 0 is nonsensical and outside the range of the sample data.

Provide an appropriate response. Each year a nationally recognized publication conducts its "Survey of America's Best Graduate and Professional Schools." An academic advisor wants to predict the typical starting salary of a graduate at a top business school using GMAT score of the school as a predictor variable. Total GMAT scores range from 200 to 800. A simple linear regression of SALARY versus GMAT using 25 data points yields the regression equation given below: y = 228x - 92,040 Give an interpretation of the y-intercept. A. We estimate SALARY to decrease $92,040 for every 1-point increase in GMAT. B. The value has no practical interpretation since a GMAT of 0 is nonsensical and outside the range of the sample data. C. We estimate the base SALARY of graduates of a top business school to be $-92,040. D. We expect to predict SALARY to within 2(92040) = $184,080 of its true value using GMAT in a straight-line model.

B. 0.4987

Provide an appropriate response. Find the area under the standard normal curve between z = 0 and z = 3. A. 0.0010 B. 0.4987 C. 0.9987 D. 0.4641

B. 0.2881

Provide an appropriate response. Furnace repair bills are normally distributed with a mean of 269 dollars and a standard deviation of 30 dollars. If 144 of these repair bills are randomly selected, find the probability that they have a mean cost between 269 dollars and 271 dollars. A. 0.7881 B. 0.2881 C. 0.5517 D. 0.2119

A. 10,080

Provide an appropriate response. How many distinct arrangements can be formed from all the letters of "students"? A. 10,080 B. 1680 C. 40,320 D. 720

A. 10,080

Provide an appropriate response. How many distinct arrangements can be formed from all the letters of "students"? A. 10,080 B. 1680 C. 720 D. 40,320

A. the least squares regression line equation explains most of the variation in the response variable.

Provide an appropriate response. If the coefficient of determination is close to 1, then A. the least squares regression line equation explains most of the variation in the response variable. B. the linear correlation coefficient is close to zero. C. the sum of the square residuals is large compared to the total variation. D. the least squares regression line equation has no explanatory value.

C. the least squares regression line equation explains most of the variation in the response variable.

Provide an appropriate response. If the coefficient of determination is close to 1, then A. the least squares regression line equation has no explanatory value. B. the sum of the square residuals is large compared to the total variation. C. the least squares regression line equation explains most of the variation in the response variable. D. the linear correlation coefficient is close to zero.

A. Type I error

Provide an appropriate response. If we reject the null hypothesis when the null hypothesis is true, then we have made a A. Type I error B. Correct decision C. Type II error D. Type α error

B. -$0.04

Provide an appropriate response. In a carnival game, a person wagers $2 on the roll of two dice. If the total of the two dice is 2, 3, 4, 5, or 6 then the person gets $4 (the $2 wager and $2 winnings). If the total of the two dice is 8, 9, 10, 11, or 12 then the person gets nothing (loses $2). If the total of the two dice is 7, the person gets $0.75 back (loses $0.25). What is the expected value of playing the game once? A. $0.00 B. -$0.04 C. -$0.42 D. $2.00

D. -$0.04

Provide an appropriate response. In a carnival game, a person wagers $2 on the roll of two dice. If the total of the two dice is 2, 3, 4, 5, or 6 then the person gets $4 (the $2 wager and $2 winnings). If the total of the two dice is 8, 9, 10, 11, or 12 then the person gets nothing (loses $2). If the total of the two dice is 7, the person gets $0.75 back (loses $0.25). What is the expected value of playing the game once? A. -$0.42 B. $0.00 C. $2.00 D. -$0.04

A. 840

Provide an appropriate response. In a contest in which 7 contestants are entered, in how many ways can the 4 distinct prizes be awarded? A. 840 B. 420 C. 210 D. 70

D. ($106.29, $112.37); we are 95% confident that the mean amount spent per dog owner for a single obedience class is between $106.29 and $112.37.

Provide an appropriate response. In a random sample of 60 dog owners enrolled in obedience training, it was determined that the mean amount of money spent per owner was $109.33 per class. Assuming the population standard deviation of the amount spent per owner is $12, construct and interpret a 95% confidence interval for the mean amount spent per owner for an obedience class. A. ($106.23, $112.43); we are 95% confident that the mean amount spent per dog owner for a single obedience class is between $106.23 and $112.43. B. ($106.78, $111.88); we are 95% confident that the mean amount spent per dog owner for a single obedience class is between $106.78 and $111.88. C. ($106.74, $111.92); we are 95% confident that the mean amount spent per dog owner for a single obedience class is between $106.74 and $111.92. D. ($106.29, $112.37); we are 95% confident that the mean amount spent per dog owner for a single obedience class is between $106.29 and $112.37.

D. (17.5, 21.7)

Provide an appropriate response. In a recent study of 42 eighth graders, the mean number of hours per week that they played video games was 19.6 with a population standard deviation of 5.8 hours. Compute the 98% confidence interval for μ. A. (14.1, 23.2) B. (18.3, 20.9) C. (19.1, 20.4) D. (17.5, 21.7)

A. 0.8522

Provide an appropriate response. Investing is a game of chance. Suppose there is a 38% chance that a risky stock investment will end up in a total loss of your investment. Because the rewards are so high, you decide to invest in four independent risky stocks. Find the probability that at least one of your four investments becomes a total loss. Round to the nearest ten-thousandth when necessary. A. 0.8522 B. 0.3624 C. 0.0906 D. 0.0209

A. skewed to the left

Provide an appropriate response. Many firms use on-the-job training to teach their employees new software. Suppose you work in the personnel department of a firm that just finished training a group of its employees in new software, and you have been requested to review the performance of one of the trainees on the final test that was given to all trainees. The mean of the test scores is 72. Additional information indicated that the median of the test scores was 76. What type of distribution most likely describes the shape of the test scores? A. skewed to the left B. symmetric C. unable to determine with the information given D. skewed to the right

C. skewed to the left

Provide an appropriate response. Many firms use on-the-job training to teach their employees new software. Suppose you work in the personnel department of a firm that just finished training a group of its employees in new software, and you have been requested to review the performance of one of the trainees on the final test that was given to all trainees. The mean of the test scores is 72. Additional information indicated that the median of the test scores was 76. What type of distribution most likely describes the shape of the test scores? A. symmetric B. skewed to the right C. skewed to the left D. unable to determine with the information given

C. (0.5496, 0.5754)

Provide an appropriate response. Many people think that a national lobby's successful fight against gun control legislation is reflecting the will of a minority of Americans. A random sample of 4000 citizens yielded 2250 who are in favor of gun control legislation. Estimate the true proportion of all Americans who are in favor of gun control legislation using a 90% confidence interval. A. (0.0327, 0.8423) B. (0.4246 , 0.4504) C. (0.5496, 0.5754) D. (0.1577, 0.9673)

A. Together Fund

Provide an appropriate response. Over the last 10 years four mutual funds all had the same mean rate of return, 12%. These mutual funds had different standard deviations as follows: Mutual Money 8%, Co-joined Investments 6%, Together Fund 4%, All for One Fund 9%. Which mutual fund investment is the most consistent in rate of return? A. Together Fund B. All for One Fund C. Mutual Money D. Co-joined Investments

C. Together Fund

Provide an appropriate response. Over the last 10 years four mutual funds all had the same mean rate of return, 12%. These mutual funds had different standard deviations as follows: Mutual Money 8%, Co-joined Investments 6%, Together Fund 4%, All for One Fund 9%. Which mutual fund investment is the most consistent in rate of return? A. Co-joined Investments B. All for One Fund C. Together Fund D. Mutual Money

C. 1.2

Provide an appropriate response. Suppose a population has a mean of 7 for some characteristic of interest and a standard deviation of 9.6. A sample is drawn from this population of size 64. What is the standard error of the mean? A. 0.15 B. 3.3 C. 1.2 D. 0.7

B. 1.2

Provide an appropriate response. Suppose a population has a mean of 7 for some characteristic of interest and a standard deviation of 9.6. A sample is drawn from this population of size 64. What is the standard error of the mean? A. 0.7 B. 1.2 C. 3.3 D. 0.15

D. 0.3

Provide an appropriate response. Suppose x is a uniform random variable with c = 10 and d = 70. Find the probability that a randomly selected observation exceeds 52. A. 0.1 B. 0.7 C. 0.9 D. 0.3

C. 0.0228

Provide an appropriate response. The average score of all golfers for a particular course has a mean of 76 and a standard deviation of 3. Suppose 36 golfers played the course today. Find the probability that the average score of the 36 golfers exceeded 77. A. 0.1293 B. 0.3707 C. 0.0228 D. 0.4772

B. 72 minutes

Provide an appropriate response. The commuting times (in minutes) of an employee for ten consecutive days are listed below. Find the median commute. 71 67 67 72 76 72 73 68 72 72 A. 71 minutes B. 72 minutes C. 67 minutes D. 73 minutes

A. 227

Provide an appropriate response. The following data are the yields, in bushels, of hay from a farmer's last 10 years: 375, 210, 150, 147, 429, 189, 320, 580, 407, 180. Find the IQR. A. 227 B. 279 C. 265 D. 253

C. 227

Provide an appropriate response. The following data are the yields, in bushels, of hay from a farmer's last 10 years: 375, 210, 150, 147, 429, 189, 320, 580, 407, 180. Find the IQR. A. 279 B. 253 C. 227 D. 265

D. 67.7 inches

Provide an appropriate response. The heights of ten female students (in inches) in a college math class are listed below. Find the mean. 65, 66, 67, 66, 67, 70, 67, 70, 71, 68 A. 70.0 inches B. 71.1 inches C. 65.5 inches D. 67.7 inches

B. There is sufficient evidence to reject the claim μ = 54.9.

Provide an appropriate response. The mean age of principals in a local school district is 54.9 years. If a hypothesis test is performed, how should you interpret a decision that rejects the null hypothesis? A. There is sufficient evidence to support the claim μ = 54.9. B. There is sufficient evidence to reject the claim μ = 54.9. C. There is not sufficient evidence to reject the claim μ = 54.9. D. There is not sufficient evidence to support the claim μ = 54.9.

D. number of items - discrete; total time - continuous

Provide an appropriate response. The peak shopping time at a pet store is between 8-11:00 am on Saturday mornings. Management at the pet store randomly selected 185 customers last Saturday morning and decided to observe their shopping habits. They recorded the number of items that a sample of the customers purchased as well as the total time the customers spent in the store. Identify the types of variables recorded by the pet store. A. number of items - continuous; total time - discrete B. number of items - continuous; total time - continuous C. number of items - discrete; total time - discrete D. number of items - discrete; total time - continuous

A. number of items - discrete; total time - continuous

Provide an appropriate response. The peak shopping time at home improvement store is between 8:00am-11:00 am on Saturday mornings. Management at the home improvement store randomly selected 180 customers last Saturday morning and decided to observe their shopping habits. They recorded the number of items that each of the customers purchased as well as the total time the customers spent in the store. Identify the types of variables recorded by the home improvement store. A. number of items - discrete; total time - continuous B. number of items - discrete; total time - discrete C. number of items - continuous; total time - discrete D. number of items - continuous; total time - continuous

B. number of items - discrete; total time - continuous

Provide an appropriate response. The peak shopping time at home improvement store is between 8:00am-11:00 am on Saturday mornings. Management at the home improvement store randomly selected 180 customers last Saturday morning and decided to observe their shopping habits. They recorded the number of items that each of the customers purchased as well as the total time the customers spent in the store. Identify the types of variables recorded by the home improvement store. A. number of items - discrete; total time - discrete B. number of items - discrete; total time - continuous C. number of items - continuous; total time - continuous D. number of items - continuous; total time - discrete

A. 61%

Provide an appropriate response. The percentage of measurements that are above the 39th percentile is A. 61% B. 71% C. cannot determine D. 39%

C. 37%

Provide an appropriate response. The percentage of measurements that are above the 63rd percentile is A. 47% B. cannot determine C. 37% D. 63%

D. 11

Provide an appropriate response. The principal at Riverside High School would like to estimate the mean length of time each day that it takes all the buses to arrive and unload the students. How large a sample is needed if the principal would like to assert with 90% confidence that the sample mean is off by, at most, 7 minutes. Assume σ = 14 minutes. A. 13 B. 10 C. 12 D. 11

A. $170

Provide an appropriate response. The repair costs for five cars which were crashed by a safety testing organization were as follows: $100, $150, $200, $250, and $150. Find the mean cost of repair. A. $170 B. $140 C. $180 D. $160

B. 0.8413

Provide an appropriate response. The tread life of a particular brand of tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 2900 miles. What is the probability a particular tire of this brand will last longer than 57,100 miles? A. 0.2266 B. 0.8413 C. 0.1587 D. 0.7266

B. 0.231

Provide an appropriate response. When 455 junior college students were surveyed,105 said that they have previously owned a motorcycle. Find a point estimate for p, the population proportion of students who have previously owned a motorcycle. A. 0.188 B. 0.231 C. 0.769 D. 0.300

A. 0.231

Provide an appropriate response. When 455 junior college students were surveyed,105 said that they have previously owned a motorcycle. Find a point estimate for p, the population proportion of students who have previously owned a motorcycle. A. 0.231 B. 0.188 C. 0.300 D. 0.769

B. Mean

Provide an appropriate response. Which is not a measure of dispersion? A. Standard deviation B. Mean C. Variance D. Range

D. Mean

Provide an appropriate response. Which measure of central tendency is not resistant to extreme values in a numeric data set? A. Median B. Parameters C. Mode D. Mean

D. Disjoint

Solve the problem. If two events have no outcomes in common they are said to be A. Independent B. Conditional C. At odds D. Disjoint

B. 0.22

Solve the problem. In the game of craps two dice are rolled and the up faces are totaled. If the person rolling the dice on the first roll rolls a 7 or an 11 total they win. If they roll a 2, 3, or 12 on the first roll they lose. If they roll any other total then on subsequent rolls they must roll that total before rolling a 7 to win. What is the probability of winning on the first roll? A. 0.50 B. 0.22 C. 0.06 D. 0.17

B. 0.0001

Solve the problem. Suppose a basketball player is an excellent free throw shooter and makes 91% of his free throws (i.e., he has a 91% chance of making a single free throw). Assume that free throw shots are independent of one another. Suppose this player gets to shoot four free throws. Find the probability that he misses all four consecutive free throws. Round to the nearest ten-thousandth. A. 0.9999 B. 0.0001 C. 0.6857 D. 0.3143

B. At least one tail

Solve the problem. The complement of 4 heads in the toss of 4 coins is A. Exactly one tail B. At least one tail C. Three heads D. All tails

D. 0.28

Solve the problem. Two dice are rolled. What is the probability of having both faces the same (doubles) or a total of 4 or 10? Round to the nearest hundredth. A. 0.06 B. 0.15 C. 0.33 D. 0.28