Assume that the mean score on an IQ test is a 100 and that the standard deviation of the scores is 15.  The highest IQ score among the people taking the test was a 160.  Calculate the z-score for the person with the highest score of 160.  Based on the z-score, is this score of 160 an outlier?  Why or why not?

Assume that the mean length of time required to complete the Columbus Marathon was 4.5 hours.  Further assume that the standard deviation of the times required to complete the race was 0.50 hours.  One runner completed the race in 5.0 hours.  Calculate the z-score for the runner with the time of 5.0 hours.  Based on this z-score, is this time of 5.0 hours an outlier?  Why or why not?

Measures of variation include

Suppose we want to estimate the average height of all students enrolled in Animal Sciences 2260 this semester.  We select a random sample of 25 students and measure their heights.  The sample mean is 68 inches and the sample standard deviation is 10 inches.  Which one of the following is the correct 95% confidence interval for the population mean?

Health care issues are receiving a greal deal of attention in both the academic and political arenas.  A sociologist recently conducted a survey of senior citizens whose net worth is too high to quality for Medicaid, but who have no private health insurance.  The ages (in years) of 8 uninsured senior citizens were as follows: Senior Citizen Age 1 66 2 70 3 64 4 88 5 74 6 72 7 87 8 79     Calculate the standard deviation of the ages of these 8 senior citizens.

An experiment results in five possible outcomes with the following probabilities:  P(A) = .10, P(B) = .25, P(C) = .20, P(D) = .15, and P(E) = .30.  What is the probability that event A does not occur?

An animal scientist wants to determine the degree of association between carcass quality grade (variable X) and selling price per pound of carcass (variable Y).  The data for a random sample of 10 Angus steer carcasses are shown in the following table. Quality grade, X Carcass price per pound, Y 5 $1.09 7 1.19 4 0.99 5 1.04 8 1.21 6 1.18 4 0.94 7 1.15 8 1.23 6 1.12 Find the covariance between carcass quality grade and carcass price per pound.

We want to test the following null and alternative hypotheses about a population proportion: Ho:  p = 0.70 Ha:  p  > 0.70 We observe 400 successes in a sample of 500 observations.  Assume that it is valid to use large-sample procedures in this problem. Calculate the test statistic needed to test the null hypothesis.  Should we reject or not reject Ho: p = 0.70 if we use a significance level of α = 0.05?  Explain.

A random sample of 4,000 U.S. citizens was asked their opinion concerning gun control.  A total of 2,600 of the 4,000 citizens in the sample stated that they are in favor of gun control legislation.  What is the point estimate of the true population proportion of U.S. citizens who favor gun control legislation?

As the sample size (n) increases, the variation in the sampling distribution of the sample means increases.