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The probability that a new advertising campaign will increase sales is assessed as being 0.80. The probability that the cost of developing the new ad campaign can be kept within the original budget allocation is 0.40. If the two events are independent, the probability that neither the cost is kept within budget nor the campaign will increase sales is: 1. a) 0.12 2. b) 0.32 3. c) 0.68 4. d) 0.88

1. a) 0.12

5. Which of the following statements about the median is not true? 1. a) It is more affected by extreme values than the arithmetic mean. 2. b) It is a measure of central tendency. 3. c) It is equal to Q2. 4. d) It is equal to the mode in bell-shaped "normal" distributions.

1. a) It is more affected by extreme values than the arithmetic mean.

A study is under way in Yosemite National Forest to determine the adult height of American pine trees. Specifically, the study is attempting to determine what factors aid a tree in reaching heights greater than 60 feet tall. It is estimated that the forest contains 25,000 adult American pines. The study involves collecting heights from 250 randomly selected adult American pine trees and analyzing the results. Identify the sample in the study. 1. a) The 250 randomly selected adult American pine trees. 2. b) The 25,000 adult American pine trees in the forest. 3. c) All the adult American pine trees taller than 60 feet. 4. d) All American pine trees, of any age, in the forest.

1. a) The 250 randomly selected adult American pine trees.

4. If the expected value of a sample statistic is equal to the parameter it is estimating, then we call that sample statistic 1. a) unbiased. 2. b) minimum variance. 3. c) biased. 4. d) random.

1. a) unbiased.

27. The owner of a fish market has an assistant who has determined that the weights of catfish are normally distributed, with mean of 3.2 pounds and standard deviation of 0.8 pound. If a sample of 25 fish yields a mean of 3.6 pounds, what is the Z-score for this observation? 1. a) 18.750 2. b) 2.500 3. c) 1.875 4. d) 0.750

2. b) 2.500

14. In left-skewed distributions, which of the following is the correct statement? 1. a) The distance from Q1 to Q2 is smaller than the distance from Q2 to Q3. 2. b) The distance from the smallest observation to Q1 is larger than the distance from Q3 to the largest observation. 3. c) The distance from the smallest observation to Q2 is less than the distance from Q2 to the largest observation. 4. d) The distance from Q1 to Q3 is twice the distance from the Q1 to Q2.

2. b) The distance from the smallest observation to Q1 is larger than the distance from Q3 to the largest observation.

In left-skewed distributions, which of the following is the correct statement? 1. a) The distance from Q1 to Q2 is smaller than the distance from Q2 to Q3. 2. b) The distance from the smallest observation to Q1 is larger than the distance from Q3 to the largest observation. 3. c) The distance from the smallest observation to Q2 is less than the distance from Q2 to the largest observation. 4. d) The distance from Q1 to Q3 is twice the distance from the Q1 to Q2.

2. b) The distance from the smallest observation to Q1 is larger than the distance from Q3 to the largest observation.

Sampling distributions describe the distribution of 1. a) parameters. 2. b) statistics. 3. c) both parameters and statistics. 4. d) neither parameters nor statistics.

2. b) statistics.

Data on the number of credit hours of 20,000 students at a public university enrolled in a Spring semester were collected. Which of the following is the best for presenting the information? 1. a) A pie chart. 2. b) A Pareto chart. 3. c) A stem-and-leaf display. 4. d) A contingency table.

3. c) A stem-and-leaf display.

Which of the following is a continuous quantitative (numerical) variable? 1. a) The color of a student's eyes 2. b) The number of employees of an insurance company 3. c) The amount of milk in a 2-liter carton. 4. d) The number of gallons of milk sold at the local grocery store yesterday

3. c) The amount of milk in a 2-liter carton.

You know that the probability of a randomly selected student will cheat on an exam is 1%. You also know that the probability of a randomly selected student will cheat on an exam knowing that his/her fellow classmate is cheating on the exam is also 1%. Which of the following is true about the event of "the randomly selected student cheating on an exam" and "his/her classmate is cheating on the exam"? 1. a) They are mutually exclusive. 2. b) They are collectively exhaustive. 3. c) They are independent. 4. d) None of the above.

3. c) They are independent.

6. Which of the following statements about the sampling distribution of the sample mean is incorrect? 1. a) The sampling distribution of the sample mean is approximately normal whenever the sample size is sufficiently large ( n 30 ). 2. b) The sampling distribution of the sample mean is generated by repeatedly taking samples of size n and computing the sample means. 3. c) The mean of the sampling distribution of the sample mean is equal to . 4. d) The standard deviation of the sampling distribution of the sample mean is equal to .

4. d) The standard deviation of the sampling distribution of the sample mean is equal to .

34. For sample size 1, the sampling distribution of the mean will be normally distributed 1. a) regardless of the shape of the population. 2. b) only if the shape of the population is symmetrical. 3. c) only if the population values are positive. 4. d) only if the population is normally distributed.

4. d) only if the population is normally distributed.

If n = 10 and = 0.70, then the mean of the binomial distribution is a) b) c) d) 0.07 1.45. 7.00 14.29

7.00

43. True or False: The median of the values 3.4, 4.7, 1.9, 7.6, and 6.5 is 4.05.

False

48. True or False: Suppose = 50 and = 10 for a population. In a sample where n = 100 is randomly taken, 90% of all possible sample means will fall between 49 and 51.

False

37. True or False: If remains constant in a binomial distribution, an increase in n will increase the variance.

True

A manufacturer of flashlight batteries took a sample of 130 batteries from a day's production and used them continuously until they were drained. The number of hours until failure is recorded. Given below is the boxplot of the number of hours it took to drain each of the 130 batteries. The distribution of the number of hours is a) right-skewed b) left-skewed c) symmetrical d) none of the above

a) right-skewed

18. If we know that the length of time it takes a college student to find a parking spot in the library parking lot follows a normal distribution with a mean of 3.5 minutes and a standard deviation of 1 minute, find the probability that a randomly selected college student will find a parking spot in the library parking lot in less than 3 minutes. a) 0.3551 b) 0.3085 c) 0.2674 d) 0.1915

b) 0.3085

24. The employees of a company were surveyed on questions regarding their educational background (college degree or no college degree) and marital status (single or married). Of the 600 employees, 400 had college degrees, 100 were single, and 60 were single college graduates. The probability that an employee of the company does not have a college degree is: a) 0.10 b) 0.33 c) 0.67 d) 0.75

b) 0.33

Suppose the time interval between two consecutive defective light bulbs from a production line has a uniform distribution over an interval from 0 to 90 minutes. What is the probability that the time interval between two consecutive defective light bulbs will be less than 10 minutes? a) 0 b) 1/9 c) 2/9 d) 8/9

b) 1/9

25. The owner of a fish market determined that the mean weight for a catfish is 3.2 pounds with a standard deviation of 0.8 pound. A citation catfish should be one of the top 2% in weight. Assuming the weights of catfish are normally distributed, at what weight (in pounds) should the citation designation be established? a) 1.56 pounds b) 4.84 pounds c) 5.20 pounds d) 7.36 pounds

b) 4.84 pounds

Suppose the time interval between two consecutive defective light bulbs from a production line has a uniform distribution over an interval from 0 to 90 minutes. What is the mean of the time interval? a) 0 b) 45 c) 90 d) cannot determine

b) 45

6. In a binomial distribution a) the variable X is continuous. b) the probability of event of interest is stable from trial to trial. c) the number of trials n must be at least 30.the results of one trial are d) dependent on the results of the other trials.

b) the probability of event of interest is stable from trial to trial.

According to the Chebyshev rule, at least what percentage of the observations in any data set are contained within 3 standard deviations around the mean? a) 67% b) 75% c) 88.89% d) 99.7%

c) 88.89%

The local police department must write, on average, 5 tickets a day to keep department revenues at budgeted levels. Suppose the number of tickets written per day follows a Poisson distribution with a mean of 6.5 tickets per day. Interpret the value of the mean. a) The number of tickets that is written most often is 6.5 tickets per day. b) Half of the days have less than 6.5 tickets written, and half of the days have more than 6.5 tickets written. c) If we sampled all days, the arithmetic average or expected number of tickets written would be 6.5 tickets per day. d) The mean has no interpretation since 0.5 ticket can never be written.

c) If we sampled all days, the arithmetic average or expected number of tickets written would be 6.5 tickets per day.

3. If a set of data is approximately normally distributed, we would find that approximately a) 2 of every 3 observations would fall between 1 standard deviation around the mean. b) 4 of every 5 observations would fall between 1.28 standard deviations around the mean. c) 19 of every 20 observations would fall between 2 standard deviations around the mean. d) All the above.

d) All the above.

If a set of data is approximately normally distributed, we would find that approximately a) 2 of every 3 observations would fall between 1 standard deviation around the mean. b) 4 of every 5 observations would fall between 1.28 standard deviations around the mean. c) 19 of every 20 observations would fall between 2 standard deviations around the mean. d) All the above.

d) All the above.