Car dealerships want to know if giving free televisions to customers increases sales. When the promotion was offered during a given week, the average number of sales per day was 40 with an estimated population variance of 100. They know that local car dealerships generally average about 20 sales per day. How do you compute the sample t score on the distribution? 40 20 100 40 20 10 20 40 100 40 20 100