A swine producer wants to know if the average weight of his…

A swine producer wants to know if the average weight of his pigs is different from the breed average of 230 lb.  He selects a random sample of 16 weights from pigs in his herd and calculates a sample mean of 220 lb and a sample standard deviation of 25 lb.  Assume that he wants to detect departure from 230 lb in either direction and that he uses a significance level of 0.10.  The correct conclusion is:

The probability of a male offspring is 1/2 and the probabili…

The probability of a male offspring is 1/2 and the probability of a female offspring is 1/2.  What is the probability that a mare will give birth to a female offspring in four consecutive years, assuming that the sexes of the offspring in different years are independent events?

In a controlled laboratory environment, independent random s…

In a controlled laboratory environment, independent random samples of 10 adults and 10 children were tested by a psychologist to determine the room temperature that each person finds most comfortable.  The study provided the following results:                                               Adults         Children Sample size                            10                 10 Sample mean (in degrees)   77.5              74.5 Sample variance                       4.5                2.5 Which one of the following is the correct 99% confidence interval for the true difference in population mean temperatures that adults and children find most comfortable?

Assuming equal numbers of observations in each of the two sa…

Assuming equal numbers of observations in each of the two samples, find the sample sizes needed to estimate the difference in population means correct to within 2.5 with probability 0.90.  From prior experience, we know that the standard deviation of population 1 is 18 and the standard deviation of population 2 is 16.