Discussion:
Q: Although there is a popular belief that herbal remedies such as ginkgo biloba and ginseng may improve learning and memory in healthy adults, these effects are usually not supported by well-controlled research. In a typical study, a researcher obtains a sample of n=36 participants and has each person take the herbal supplements every day for 90days. At the end of the 90 days, each person takes a standardized memory test. For the general population, scores fromt he test are normally distributed with a mean of 80 and a standard deviation of 18. The sample research participants had an average of M=84.
a-Assuming a two-tailed test, state the null hypothesis in a sentence that includes the two variables being examined.
b-Using symbols, state the hypothese (Ho and H1)for the two-tailed test.
c-Sketch the appropriate distribution, and locate the critical region for alpha=.05
d-Calculate the test statistic (z-score) for the sample.
e-What decision should be made about the null hypothesis, and what decision should be made about the effect of the herbal supplements.