5. 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

(Persson, Bringlov, Nilsson, & Nyberg, 2004). In a typical study, a researcher obtains a sample of n 36 participants and has each person take the herbal supplements every day for 90 days. At the end of the 90 days, each person takes a standardized memory test. For the general population, scores from the test are normally distributed with a mean of 80 and a standard deviation of  18. The sample of research participants had an average of M 84.

a. In a sentence, state the null hypothesis being tested.

b. Using symbols, state the null hypothesis and the alternative hypothesis.

c. Conduct the hypothesis test using a two-tailed test with  .05.