posted by Barbara .
For each of the following samples that were given an experimental treatment, test whether these samples represent populations that are different from the general population: A. a sample of 10 with a mean of 44. B.a sample of 1 with a mean of 48. The general population of individuals has a mean of 40, a standard deviation of 6, and follows a normal curve. For each sample, carry out a Z test using the five steps hypothesis testing with a two-tailed test at the .05 significance level, and make a drawing of the distributions involved.
Here are a few hints:
1. Use a one-sample z-test for both A and B, which is:
z = (sample mean - population mean)/(standard deviation divided by the square root of the sample size)
2. Find the critical or cutoff value to reject the null using a z-table for .05 level of significance for a two-tailed test. If the test statistic exceeds the critical value you find in the table, reject the null and conclude a difference. If the test statistic does not exceed the critical value you find in the table, do not reject the null. You cannot conclude a difference in this case.
I hope this will help get you started.