t-statistics vs. z-statistics - Why is a t-statistic, as opposed to a z-statistic, used to test small populations? When does the t-statistic approximate the z-statistic?
Find the test statistic - A sample of 25 households in Prolific City revealed a mean of 7.5 residing members and a standard deviation of 3. If the mean household size for the nation is 4.2, what is the value of the test statis ...