3. The following questions test your understanding of confidence intervals. [10 marks] a. Let us determine the amount of time you spend each day exercising. For a given week, the values in minutes are: 51, 24, 16, 88, 63, 28, and 59. Assume that the amount of time you spend on exercise each day is normally distributed. Develop a 90% confidence interval for the population average amount of time. . Refer to part (a). How do you interpret this confidence interval? In a survey of 600 individuals, 16.4% indicated that they had fallen asleep in front of the TV in the past week. What is the 98% confidence interval for the population proportion? The number of widgets produced each hour is normally distributed with a standard deviation of 7.4. For a random sample of 15 hours, the average number of widgets produced was 587.3. Find the upper and lower confidence limits of a 98% confidence interval for the population mean number of widgets produced in an hour. A 95% confidence interval estimate for a population mean is determined to be 63 to '70. If the confidence level is reduced to 92.5%, the confidence interval for ,u becomes narrower. Is this statement true or false