A market researcher is interested in determining the average income for families in San Mateo County, California. To accomplish this, she takes a random sample of 300 families from the county and uses the data gathered from them to estimate the average income for families of the entire county. This process is an example of _______.

descriptive statistics

nonparametric statistics

inferential statistics

nominal data

census

Lucy Baker is analyzing demographic characteristics of two television programs, American Idol (population 1) and 60 Minutes (population 2). Previous studies indicate no difference in the ages of the two audiences (The mean age of each audience is the same.) Lucy plans to test this hypothesis using a random sample of 100 from each audience. Her null hypothesis is ____________.

m₁ - m₂ = 0

m₁ - m₂< 0

m₁ - m₂ 0

m₁ - m₂> 0

m₁ - m₂< 1

James Desreumaux, VP of Human Resources of American First Banks (AFB), is reviewing the employee training programs of AFB banks. His staff randomly selected personnel files for 100 tellers in the Southeast Region and determined that their mean training time was 25 hours. Assume that the population standard deviation is 5 hours. The 95% confidence interval for the population mean of training times is ________.

16.78 to 33.23

23.32 to 35.46

15.20 to 34.80

24.18 to 25.82

24.02 to 25.98