QUESTION 1 Suppose that you own a coffee shop. You want to estimate the population mean of the daily sales. A sample of past 5 days of sales data provided the following information: Day 2 3 4 5 Coffees sold (in cups) 94 100 90 89 82 You are going to use the sample average as a point estimator for the population mean. You also want to measure the accuracy of your estimator, and use the standard error as the measure of the accuracy. What is the standard error of your point estimator? When you calculate a variance or a standard deviation, use the sample version formula. O a. Square-root of 3.8 O b. Square-root of 4.3 O C. Square-root of 6.8 O d. Square-root of 5.3 O e. Square-root of 8.8