Exam 8: Confidence Interval Estimation

If two random samples of sizes 30 and 35 are selected independently from two populations whose means are 85 and 90,then the mean of the sampling distribution of the sample mean difference, ,equals 5.

Two independent samples of sizes 20 and 25 are randomly selected from two normal populations with equal variances.In order to test the difference between the population means,the test statistic is:

There are,generally speaking,two types of statistical inference.They are:

For a given confidence level,the procedure for controlling interval length usually begins with the specification of

A confidence interval is an interval estimate for which there is a specified degree of certainty that the actual true value of the population parameter will fall within the interval.