Answer all questions and show all of your work. 1. When the author was conducting research for this chapter, he could find no information about the percentage of adults who make online purchases, yet that information is extremely important to online stores as well as brick and mortar stores. If the author were to conduct his own survey, how many adults must be surveyed in order to be 95% confident that the sample percentage is in error by no more than two percentage points? (a) Assume that a recent poll showed that 70% of adults make online purchases. (b) Assume that we have no prior information suggesting a possible value of the population proportion. 2. Assume that we want to estimate the mean IQ score for the population of statistics students with o = 15 known. How many statistics students must be randomly selected for IQ tests if we want 95% confidence that the sample mean is within 3 IQ points of the population mean