Problem 5: The mean number of close friends for the population of people living in the U.S. is 5.7. The standard deviation of scores in this population is 1.3. An investigator predicts that the mean number of close friends for introverts will be significantly different from the mean of the population. The mean number of close friends for a sample of 36 introverts is 6.5. Do these data support the investigator's prediction? Use an alpha level of .05. Problem 6: The mean number of close friends for the population of people living in the U.S. is 5.7. An investigator predicts that the mean number of close friends for introverts will be significantly less than the mean of the population. The mean number of close friends for a sample of 26 introverts is 6.5. The standard deviation of scores in this sample is 1.3. Do these data support the investigator's prediction? Use an alpha level of 05