Although there is the popular belief that herbal remedies like Ginkgo biloba and Ginseng might enhance learning and memory in healthy adults, these effects are basically not supported by well-controlled research (Peressson, Bringlov, Nilsson, & Nyberg, 2004). In a typical study, a researcher obtains the sample of n=36 participants and has each person take the herbal supplements everyday for 90 days. At the end of the 90 days, each person takes the standardized memory test. For general population, scores from the test are basically distributed with the mean μ = 80 and the standard deviation of σ = 18. The sample of research participants had average of M = 84.

a. In the sentence, state the null hypothesis to be tested.

b. By using symbols state the null hypothesis and alternative hypothesis

c. Conduct the hypothesis test using the two-tailed test with = 0.05.