An online clothing company decides to investigate whether offering their customers a coupon upon completion of their first purch
ase will encourage them to make a second purchase. To do so, the company programs the website to randomly select 100 first time customers. Sixty of these customers are randomly selected to receive a coupon for $5 off their next purchase, to be made in the next 30 days. The other 40 customers are not offered a coupon. The table below shows the number of customers in each group that made a second purchase within 30 days of their first purchase. Based upon the table, is “yes, made a second purchase” independent of “yes, being sent a coupon”?
A) Yes, exactly half of the customers made a second purchase and half did not. (B) Yes, the largest count in the table comes from those who were sent a coupon and made a second purchase within 30 days. (C) No, the probability of making a second purchase is not equal to the probability of making a second purchase given that a coupon was sent. (D) No, the probability of making a second purchase is the same whether or not a coupon was sent. (E) It is impossible to draw a conclusion about independence because a coupon was not sent to exactly half of the customers.
To get from 4.5 to 5.4, you need to add 0.9. If you add 0.9 two more times, you get 7.2. Therefore, the middle term should be 6.3. I don't know if you made a typo and forgot the decimal when writing the options cause it says "63", but I believe the answer is 6.3.
