8. For the past 50 days, daily sales of a specialty product in a large grocery store have been recorded: Units Sold Number of Times 10 8 20 18 30 10 40 8 50 6 a. What is the average number of units sold? b. What is the standard deviation? c. What is a 68.26% confidence interval? Please interpret. d. Suppose that the following random numbers were obtained: .86 .23 .73 .40 .95