Author Question: The width of a confidence interval estimate of the population mean increases when the: a. level of ... (Read 102 times)

AEWBW · **on:** Jun 24, 2018

The width of a confidence interval estimate of the population mean increases when the:
a. level of confidence increases
b. sample size decreases
c. value of the population standard deviation increases
d. All of these choices are true.

Question 2

To test the validity of a multiple regression model, we test the null hypothesis that the regression coefficients are all zero by applying the:
a. F-test c. z-test
b. t-test d. None of these choices.