1. Is there a home field advantage in professional baseball games? Emotional support from the fans and familiarity with the field seem to make a difference as the home team has won in approximately 5/9 of World Series games. Assuming this probability is constant and games are independent, if the home team wins the first game, what is the probability that the home team also wins the next two games?

A.) (5/9)^2B.) (5/9)^3C.) 3(5/9)^2(4/9)D.) 1-(5/9)^3E.) 1-(4/9)^2

2. A national parent organization is concerned that middle school student are spending too much time (more than 8 hours per week) with home video game consoles like the Xbox 360, Wii, and Play Station 3. A study is conducted sampling 150 students, and the resulting sample mean is 7.95 hours. What is the appropriate alternative hypothesis for this study?

A.) Ha: µ < 8B.) Ha: µ > 8C.) Ha: µ < 7.95D.) Ha: µ > 7.95E.) Ha: µ≠ 7.95

3. During one of the recent fiscal controversies, only 18 percent of Americans approved of the job Congress was doing. A national polling organization wants to construct a 99 percent confidence interval of the current percent with a margin of error of ±2 percent. Assuming that the current percent is roughly what it was before, which of the following will lead to a correct calculation of sample size n?

A.) (2.326)√(0.5)(0.5)/n ≤ .02B.) (2.576)√(0.5)(0.5)/n ≤ .01C.) (2.326)√(0.18)(0.82)/n ≤ .01D.) (2.576)√(0.18)(0.82)/n ≤ .01E.) (2.576 )√(0.18)(0.82)/n ≤ .02

4. A weight loss program had the participants eat different types of fiber (bran, gum, or a control cracker) before each meal. All participants experienced either high, medium, or low weight loss. The resulting contingency table is given below.

Low Medium HighBran 23 15 12Gum 14 18 18Control 27 14 9With a chi-square value of 7.49 is there statistical evidence of a relationship between type of bran and amount of weight loss?

A.)No, because the P-value is greater than .10.B.) Yes, .05<P<.10, indicating some evidence of a relationship.C.) Yes, .01<P<.05, indicating evidence of a relationship.D.) Yes, .001<P<.01, indicating strong evidence of a relationship.E.) Yes, P<.001 indicating very strong evidence of a relationship.

5.

6. A company bids on three independent contracts with probabilities of winning the contracts .1, .25, and .3, respectively. What is the probability of winning at least one contract?

A) .35B) .4725C) .5275D) .65E) .9925

7. In 1798 Henry Cavendish used a torsion balance to estimate the density of the Earth as 5.42 times the density of water. A modern day geologist runs a hypothesis test with Ha: ≠ 5.42 and obtained a P-value of .08. If the geologist had run a one-sided test with the same data, what is true about the possible resulting P-value(s)?

A) The only possible P-value is 0.4.B) The only P-value is .08.C) The only possible P-value is .16.D) The possible P-values are .04 and .92.E) The possible P-values are .04 and .96.

8. Car insurance policies for teenagers have higher premiums than for adult drivers because teenagers are considered to be a high-risk population. Suppose the average yearly cost of teenage (ages 16-19) insurance is $3,025 with a standard deviation of $430. Is there sufficient information to answer either or both of the questions:

I. What is the probability that a randomly chosen teenage driver pays over $3,000 a year for auto insurance?

II. What is the probability that the average amount paid in an SRS of 50 teenage drivers is more than $3,000 a year?

A) Insufficient information to answer either question.B) Sufficient information to answer question I, but not question II.C) Sufficient information to answer question II, but not question I.D) Sufficient information to answer both questions.E) With a sample size of 50, the sampling distribution is approximately normal with mean $3,025 and

standard deviation $430/√50.

9. The 40 yard dash is an important diagnostic evaluation tool for all positions in both collegiate an professional football recruiting. Which of the following is the best interpretation of a 95 percent confidence interval of (4.67, 4.87) seconds for the mean 40 yard dash time?

A) Ninety-five percent of all players run the 40 yard dash in between 4.67 and 4.87 seconds.B) Ninety-five percent of all players have a mean 40 yard dash time between 4.67 and 4.87 seconds. C) Players run the 40 yard dash in between 4.67 and 4.87 seconds 95 percent of the time. D) We are 95 percent confident that for any given player his 40 yard dash time is between 4.67 and

4.87 seconds.E) We are 95 percent confident that the mean 40 yard dash time is between 4.67 and 4.87 seconds.

10. Babe Ruth had a career batting average of p= .342, pretty amazing for a player known for his homeruns! Consider two random samples, one of 30 at bats and one of 60 at-bats. Which of the following is an incorrect statement about the sampling distribution for p with n=30 and 60?A) The shape of the sampling distribution for n=60 is closer to a normal distribution than that for n=30.B) The mean of the sampling distribution for n=60is larger than that for n=30.C) The standard deviation of the sampling distribution for n=60 is less than that for n=30.D) The mean of the sampling distribution for p is equal to the expected number of hits divided by the sample size.E) The standard deviation of the sampling distribution for p is equal to the standard deviation for the expected number of hits divided by the sample size.

Free Response Question (Counts as 25% of your grade)

Write a letter to incoming Juniors and Seniors of AP Stats – write about what they need to do to prepare for this class, to make it through this class, and to do well on the AP Exam. Use complete sentences and correct grammar. It needs to be AT LEAST 3 paragraphs.