# Question

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?

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