2.A health insurance company is interested in the cholesterol levels for individuals ages 40 or older. A random sample of 100 individuals was chosen from the target population. The following information was obtained from the sample: average = 158 mg, median = 159 mg, s.d. = 20 mg. One individual has a cholesterol level at 175 mg. Based on only the summary statistics, is this an unusually high level of cholesterol for someone from this population? Why or why not?

No, because it is not above 200 mg, the recommended maximum adult cholesterol level.

Yes, because it is better to have a low cholesterol level.

Yes, because 175 is 17 mg higher than the mean cholesterol level.

No, because 175 is less than one standard deviation above the mean

3.Scores on a standardized test are normally distributed, perfectly symmetric and mound shaped, with a mean of 100 and astandard deviation of 20. If these scores are converted to standard normal z scores,which of the following statements will be correct?

Both the mean and median score will equal 0.

The mean will equal 0, but the median cannot be determined.

The mean of the standardized z-scores will equal 5.

The mean of the standardized z-scores will equal 100.

4.A doctor collects a large set of heart rate measurements that approximately follow a normal distribution. He only reports 3 statistics, the mean = 110 beats per minute, the minimum = 65 beats per minute, and the maximum = 155 beats per minute. Which of the following is most likely to be the standard deviation of the distribution?

5

15

35

90

5.At a large high school, students took a series of advanced tests. Each test covered a different subject area, had a different number of items, and a different mean and standard deviation. One of the students, Marquita, wants to see on which tests she performed the best. Which of the following methods should she use?

Compare her total scores on each test.

Compare her standardized z score on each test.

Compare her percent correct for each test.

All of the above would lead to the same conclusion.

8.Assume that the distribution of weights of adult men in the United States is normal with mean 190 pounds and standard deviation 30 pounds. Bill's weight has a z-score of 1.2.Which of the following is true?

Bill weighs less than 220 pounds.

Bill weighs more than 220 pounds.

Bill's weight is in the lower 2.5% of men's weights.

Bill's weight is in the upper 2.5% of men's weights.

10.A game company created a little plastic dog that can be tossed in the air. It can land either with all four feet on the ground, lying on its back, lying on its right side, or lying on its left side. However, the company does not know the probability of each of these outcomes. They want to estimate the probabilities. Which of the following methods is most appropriate?

Since there are four possible outcomes, assign a probability of 1/4 to each outcome.

Toss the plastic dog many times and see what percent of the time each outcome occurs.

Simulate the data using a model that has four equally likely outcomes.

None of the above.

11.A student participates in a Coke versus Pepsi taste test. She correctly identifies which soda is which four times out of six tries. She claims that this proves that she can reliably tell the difference between the two soft drinks. You have studied statistics and you want to determine the probability of anyone getting at least four right out of six tries just by chance alone. Which of the following would provide an accurate estimate of that probability? Remember, you are trying to prove that four out of six is unusual or not unusual if one truly does not know the taste difference.

Simulate this on the computer with the probability of 50% of guessing the correct soft drink on each try, and calculate the percent of times there are four or more correct guesses out of six trials.

Repeat this experiment with a very large sample of people and calculate the percentage of people who make four correct guesses out of six tries.

Have the student repeat this experiment many times and calculate the percentage of times she correctly distinguishes between the brands.

No need to run any further tests, since 4 out of 6 is better than half of the time, we would say the student's claim is correct.

13.A standardized measure of achievement motivation is normally distributed, with a meanof 35 and a standard deviation of 14. Higher scores correspond to more achievementmotivation.

Gatoscored 49 on this exam.Gatoscored higher than what proportion of thepopulation?

.84

.32

.68

.49

14.Colin is flipping a fair coin. Heads has just come up 5 times in a row! The chance of getting heads on the next throw is

less than the chance of getting tails since we are due for a tails.

equal to the chance of getting tails since the flips are independent.

greater than the chance of getting tails since heads seem to be coming up.

is 1 out of 2^6.

18.The distribution of heights of adult men is approximately normal with a mean of 69 inches and a standard deviation of 2 inches. Bob's height has a Z-score of -.5 when compared to all adult men. Which of the following is true?

Bob is shorter than 69 inches tall.

Bob's height is half of a standard deviation below the mean.

Bob is 68 inches tall.

All of the above.

21.Bob and Bill each bought one ticket for a lottery each week for the past 100 weeks. Bill has not won a single prize yet. Bob just won a $20 prize last week. Who is more likely to win a prize this coming week if they each buy only one ticket?

Bill.

Bob.

They have an equal chance of winning

22.Suppose you read on the back of a lottery ticket that the chances of winning a prize are 1 out of 10. Select the best interpretation.

You will win at least once out of the next 10 times you buy a ticket.

You will win at most once out of the next 10 times you buy a ticket.

You will win exactly once out of the next 10 times you buy a ticket.

You should win once out of the next 10 times but it is not for sure.

23.Chris is enrolled in a college algebra course and earned a score of 260 on a math achievement test that was given on the first day of class. The instructor looked at two distributions of scores, one is the distribution for all freshmen who took the test, and the other is a distribution for students enrolled in this algebra course. Both are approximately normally distributed and have the same mean, but the distribution for the algebra course has a smaller standard deviation. A z-score is calculated for Chris' test score in both distributions (all freshmen and all freshmen taking algebra). Given that Chris' score is well above the mean, which of the following would be true about these two z-scores?

The z-score based on the distribution for the algebra students would be higher.

The z-score based on the distribution for all freshmen would be higher.

The two z-scores would be the same.

It cannot be determined.