If you wish to estimate the difference between two population means and the population variances are known, a 99% confidence interval estimate can be found by using which of the following critical values?
A) 1.615
B) 1.96
C) 2.33
D) 2.575

Question

Quizplus · Accepted Answer

When estimating the difference between two population means with known variances, and aiming for a 99% confidence interval, the critical value used is from the standard normal (Z) distribution. For a 99% confidence level, the critical value is 2.575, which corresponds to the tails of the distribution (0.5% on each tail in a two-tailed test).

If You Wish to Estimate the Difference Between Two Population