Question

A population has a mean of 400 and a standard deviation of 90. Suppose a sample of size 125 is selected and  is used to estimate . Use z-table.

1. What is the probability that the sample mean will be within +/- 8 of the population mean (to 4 decimals)? (Round z value in intermediate calculations to 2 decimal places.)
     
   
2. What is the probability that the sample mean will be within +/- 14 of the population mean (to 4 decimals)? (Round z value in intermediate calculations to 2 decimal places.)
   

The National Football League (NFL) polls fans to develop a rating for each football game. Each game is rated on a scale from 0 (forgettable) to 100 (memorable). The fan ratings for a random sample of 12 games follow.

56	60	87	73	72	73
21	57	81	78	83	74

a. Develop a point estimate of mean fan rating for the population of NFL games (to 2 decimals).

b. Develop a point estimate of the standard deviation for the population of NFL games (to 4 decimals).

Answer 1