Acritically important aspect of customer service in a supermarket is the waiting time at the checkout (defined as the time the customer enters the line until he or she is served). data were collected during time periods in which a constant number of checkout counters were open. the total number of customers in the store and the waiting times (in minutes) were recorded. the results are given below. day customers time1 15.00 1.50 2 18.00 1.203 9.00 0.804 7.00 0.505 19.00 2.006 30.00 2.507 27.00 3.008 13.0 2.009 11.00 1.7010 9.00 0.5011 21.00 2.0012 35.00 5.2013 25.00 2.3014 8.00 0.2015 16.00 0.70a. construct a scatter plot. b. assuming a linear relationship, use the least-squares method to determine the regression coefficients b0 and b1.c. interpret the meaning of the slope, in this problem. d. predict the waiting time when there are 20 customers in the store. you used the number of customers to predict the waiting time at the checkout line in a supermarket. using the results of that problem, a. determine the coefficient of determination, r2, and interpret its meaning. b. determine the standard error of the estimate. c. how useful do you think this regression model is for predicting the waiting time at the checkout line in a supermarket?