The mean gross annual incomes of the population of certified tack welders are normally distributed with the mean

of $20,000 and a standard deviation of $5,000. ;The ship building association wishes to find out whether their tack welders earn $20,000 annually or not. ;A sample of 81 ship building tack welders revealed a sample mean of $21,111. ;What is the result of the test?

z = 2, Reject the null hypothesis, the ship building tack welders do not earn $21,111.

z = 2, Accept the null hypothesis, the ship building tack welders do earn $20,000.

z = 2, Reject the null hypothesis, the ship building tack welders do not earn $20,000. They earn less.

z = 2, Reject the null hypothesis, the ship building tack welders do earn $20,000. They earn more.

z = 2, Reject the null hypothesis, the ship building tack welders do not earn $20,000. They earn more.

z = 2, Fail to reject the null hypothesis, the ship building tack welders do not earn $20,000. They earn more.

The paired t-test is used for what type of samples?

30 or more

large

multiple groups

independent

dependent

nominal data

To compare a sample to a sample when n < 30, which distribution should be used?

decision rule

the z distribution

the t distribution

the F distribution

the chi-square distribution

the alpha distribution

p-value distribution

To compare a sample to a sample when n ≥ 30, which distribution should be used?

decision rule

the z distribution

the t distribution

the F distribution

the chi-square distribution

the alpha distribution

p-value distribution

What is another name for the alternate hypothesis?

null hypothesis

alternate hypothesis

research hypothesis

decision rule

critical hypothesis