A random sample of n = 25 individuals is selected from a population with u = 20,
Question:
A random sample of n = 25 individuals is selected from a population with u = 20, and treatment is administered to each individual in the sample. After treatment, the sample mean is found to be M = 22.2 with SS = 384.
a. How much difference is there between the mean for the treated sample and the mean for the original population? (Note; In a hypothesis test, this value forms the numerator of the t statistic.)
b. If there is no treatment effect, how much difference is expected between the sample mean and its population mean? That is, find the standard error for M. (Note: In a hypothesis test, this value is the denominator of the t statistic.)
c. Based on the sample data, does the treatment have a significant effect? Use a two-tailed test with a = .05.
Essentials of Statistics for the Behavioral Sciences
ISBN: 978-1285056340
8th Edition
Authors: Frederick J Gravetter, Larry B. Wallnau