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The body weight in pounds (variable X) and fleece weight in pounds (variable Y) of a random sample of four ewes are as follows: Body weight, lb (X)            Fleece weight, lb (Y)           140                                            9           145                                          10           155                                          10           160                                          12                                                                                      Derive the equation for the regression line.  What would be the predicted fleece weight of a ewe that weighs 152 lb?

A farmer weighs his calves on the day they are weaned.  The weight of the lightest calf is 300 lb and the weight of the heaviest calf is 650 lb.  Based on this information, which measure of variation could be calculated?

Suppose a 99% confidence interval for the population mean for weight of cows of a certain breed turns out to be (800 lb, 1400 lb).  To make more useful inferences from the data, it is desired to reduce the width of the confidence interval.  Which of the following will result in a reduced width of the confidence interval?

Assume that the mean length of time required to complete the Columbus Marathon was 4.5 hours and that the standard deviation of the times was 0.50 hours.  Assume that the racing times were approximately normally distributed.  Only 10% of the runners would be expected to complete the race in less than x hours.  Find the value of x.

The Central Limit Theorem is important in statistics, because:

We construct the following 95% confidence interval for the mean weaning weight of a population of Angus calves:  (500 lb, 600 lb) Which one of the following statements is the correct interpretation of this 95% confidence interval?

In order to compare the means of two populations, independent random samples are selected from each population, with the following results:                                             Sample 1     Sample 2 Sample size                            500                400 Sample mean                       5,280             5,240 Sample standard deviation     150                200 Construct a 95% confidence interval for the difference in the two population means.

A swine producer reads a report stating that the average litter size in the US is 7.8 pigs per litter.  However, he feels that the average litter size on his farm is not 7.8 pigs/litter (he wants to detect departure in either direction from the hypothesized mean of 7.8 pigs/litter).  To test his hypothesis, he reviews his records for the past year and randomly selects 16 litters, which averaged 8.0 pigs/litter.  The standard deviation is 1 pig/litter. State the null and alternative hypothesis.

The table shown below summarizes the 10 winners of the World Series from 1990 to 2000 by division and league.  There was no World Series in 1994 due to a strike by the players.  One of these 10 World Series winners is to be chosen at random.                                                     League                                                   National        American                        Eastern          2                     6 Division           Central          1                     1                         Western        0                     0 Given that the winning team is a member of the American League, what is the probability that the winning team plays in the Eastern Division?

The American Journal of Public Health published a study of the relationship between passive smoking and nasal allergies in Japanese female students.  The study revealed that 80% (i.e., p = 0.80) of the students from heavy-smoking families showed signs of nasal allergies on physical examinations.  Consider a sample of 10 Japanese female students exposed daily to heavy smoking in their families.  What is the probability that exactly 8 of the 10 students will have nasal allergies?