A speed training program was effective in improving the 40-yard sprint times of high school athletes.  A study of 500 high school athletes was conducted to estimate p, the true proportion of all high school athletes who attained improved sprint times after participating in the speed training program.  The study showed that 425 of the 500 athletes had improved sprint times. Perform the calculations needed to determine if the sample size of n = 500 is large enough for large-sample confidence interval procedures to be valid.  Is the sample size large enough?

The heights in inches of young growing trees were measured at a nursery and used to construct the following stem-and-leaf display using the first digit as the stem and the second digit as the leaf: Stem                       Leaves                                     3               2     4 4               0     3     4     5     7     8     9 5               0     1     2     3     4     5 6               1     2     5     6     7 7               0     1 8 9               8 Construct a box plot for these data.  List any suspect or highly suspect outliers for this dataset.

Suppose that a random sample of 40 measurements is selected from a population with a mean of 64 and a variance of 64.  What is the mean and standard deviation of the sampling distribution of the sample mean?

The person in charge of genetic evaluation of beef cattle wants to know if birth weights of calves are influenced by breed and if they are influenced by the region of the U.S. (i.e., Northern U.S. vs Southern U.S.) in which the calf is born.  She has heard that calves born in the South are usually lighter at birth than are calves born in the North.  In order to answer these questions, she sets up a 2 x 3 factorial experiment with 3 replications and obtains the birth weights (in pounds) shown in the following table:                   Angus       Charolais       Simmental North             85                93                 91                       85                92                 92                       83                94                 92   South            85                84                  82                      76                85                   83                      74                83                   83       The partially completed ANOVA table is as follows: Source               df             SS            MS          F       Total                                 548.00 Location Breed                               174.33       87.165     13.643 Location x breed                  9.00         4.500 Error                                                                                         Calculate the mean square (MS) for Error.

USA Today reported the results of a study that suggests frequently heading the ball in soccer lowers players’ IQs.  A psychologist tested 60 male soccer players ages 14 to 29 who played soccer up to five times per week.  Players who averaged 10 or more headers per game had an average IQ of 103, whereas players who headed the ball one or fewer times per game had an average IQ of 112.  The population of interest in this study is:

Which one of the following confidence intervals would be the widest?

The value of a sample statistic will vary from sample to sample.

Starting salary and GPA of students who graduate from OSU are examples of ____________ data.

An experiment results in four possible outcomes with the following probabilities:  P(A) = 0.10, P(B) = 0.15, P(C) = 0.20, and P(D) = 0.55.  Assume that these four events are mutually exclusive.  What is the probability that event B, C, or D occurs?

We want to test the hypothesis that the mean number of credit hours taken per semester by OSU undergraduates is less than 16 hours.  Therefore, we obtain a random sample of credit hours for 49 students. The sample mean is 15 hours and the sample standard deviation is 4 hours.  We want to test:    Ho:  μ = 16 hours    Ha:  μ < 16 hours using a significance level (α) = 0.01. What is the critical value needed to test the null hypothesis in this problem?