When performing a hypothesis test about the population mean, a possible reason for the failure of rejection of the null hypothesis is that there's an insufficient sample size to achieve a powerful test. Using a small data set, Minitab is used to check for normality of the data, to perform a 1-Sample t test, and to compute Power and Sample Size for 1-Sample t.
...statisticians are the new sexy vampires, only even more pasty. A quote by American playwright, columnist, and humorist Paul M. Rudnick (1957 - ) from his November 19, 2012 essay "A Date with Nate" in "The New Yorker". The essay arose after the correct prediction of the winner of the presidential race in all 50 states in 2012 by statistician Nate Silver
This page provides a t-table with degrees of freedom 1-30, 60, 120, and infinity and seven levels of alpha from .1 to .0005.
This applet demonstrates the concept of power. Users select the hypothesized mean, the alternative mean, the sample size, and the number of samples. The applet shows the hypothesized histogram and the alternative histogram. Users then select either the level of significance and set alpha or the rejection region and set the test statistic. The applet then shows the p-value (in red) and power (in green). User can also determine the direction of the test by clicking the inequality sign.