Suppose a population consisted of 20 items. How many different samples of n = 3 are possible?

A. 1140

B. 6840

C. 20

D. 120

The difference between the sample meanand the population mean is called the

A. Population standard deviation.

B. Population mean.

C. Standard errorof the mean.

D. Samplingerror.

We wish to develop a confidence intervalfor the population mean. The population follows the normal distribution, the standard deviation of the population is 3, and we have a sample of 10 observations. We decide to use the 90% level of confidence. The appropriate value of to represent the level of confidence is

A. t=1.812

B. z =1.65

C. t=1.833

D. z=1.96

A confidence interval

A. Always includes the population parameter.

B. Decreases in width as the sample size is increased.

C. Cannot include a value of 0

D. None of these

Which of the following statements is not a characteristic of the t distribution?

A. Like z there is only one t distribution.

B. It is a continuous distribution.

C. It is symmetrical.

D. It has a mean of 0.

Answers of multiple choice questions on hypothesis testing and confidence interval