A random sample is selected from a normal population with a mean of u treatment is administered to the individuals in the sample, the sample mean is found to be M = 196. How large a sample is...

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Extracted text: A random sample is selected from a normal population with a mean of u treatment is administered to the individuals in the sample, the sample mean is found to be M = 196. How large a sample is necessary for this sample mean to be statistically significant using a two-tailed test with a = .05? = 200 and a standard deviation of o = 12. After a a. 30 Correct. To be statistically significant with a = needs to be 1.96 standard errors away from the norm. Since 196 is 4 away from 200, this means the standard .05, 196 b. 35 c. 40 12 2.04 = O d. 70 Solving, error must be 2.04. This means that we get n = 34.6. So we need a population of n = 35. See 8.1: The Logic of Hypothesis Testing.