# Question: A random sample is selected from a normal population with

A random sample is selected from a normal population with a mean of µ = 100 and a standard deviation of s = 20. After a treatment is administered to the individuals in the sample, the sample mean is found to be µ = 96.

a. How large a sample is necessary for this sample mean to be statistically significant? Assume a two-tailed test with a = .05.

b. If the sample mean were µ = 98, what sample size would be needed to be significant for a two tailed test with a = .05?

a. How large a sample is necessary for this sample mean to be statistically significant? Assume a two-tailed test with a = .05.

b. If the sample mean were µ = 98, what sample size would be needed to be significant for a two tailed test with a = .05?

## Relevant Questions

Under what circumstances is a t statistic used instead of a z-score for a hypothesis test? The librarian at the local elementary school claims that, on average, the books in the library are more than 20 years old. To test this claim, a student takes a sample of n = 30 books and records the publication date for ...An example of the vertical-horizontal illusion is shown in the figure. Although the two lines are exactly the same length, the vertical line appears to be much longer. To examine the strength of this illusion, a researcher ...The following sample was obtained from a population with unknown parameters. Scores: 6, 12, 0, 13, 4, 7 a. Compute the sample mean and standard deviation. b. Compute the estimated standard error for M. It appears that there is some truth to the old adage "That which doesn't kill us makes us stronger." Seery, Holman, and Silver (2010) found that individuals with some history of adversity report better mental health and ...Post your question