Author Question: Drake Marketing and Promotions has randomly surveyed 200 men who watch professional sports. The men ... (Read 81 times)

jc611 · **on:** Jun 24, 2018

Drake Marketing and Promotions has randomly surveyed 200 men who watch professional sports. The men were separated according to their educational level (college degree or not) and whether they preferred the NBA or the National Football League (NFL).

The results of the survey are shown:Sports Preference College Degree No College DegreeNBA 40 55NFL 10 95What is the probability that a randomly selected survey participant prefers the NFL?A) 0.5250
B) 0.2000
C) 0.6050
D) 0.5880

Question 2

In estimating a population mean, under what conditions would the t-distribution be used?

What will be an ideal response?

bigcheese9 · **Reply #1 on:** Jun 24, 2018

Answer to Question 1

A

Answer to Question 2

The t-distribution is used to obtain the critical value for a confidence interval estimate for the population mean when the value for the population standard deviation is unknown or the sample size is reasonably small. Technically, the t-distribution can be used when the standard deviation is not known, but since the t-distribution and the z-distribution converge for large samples, it generally does not matter in cases where the sample size is large. It should be noted that the t-distribution is based on the assumption that the population is normally distributed. However, the t-distribution is usable as long as the population is reasonably symmetric.