3. An electronics store kept records of sales of tablets for the previous month. Those buying a tablet had the option of buying an additional warranty for their item. It was also recorded whether the customer paid with credit card or cash (no other payment methods were allowed). Some summary information is below. Please answer the questions below the table. It may help to orgaize the information into a two-way table.

Tablets purchased with credit card 122

Tablets sold with warranty 36

Tablets sold with warranty purchased with credit card 24

Total tablets sold 200

(a) What percentage of tablets were purchased with cash?

(b) What percentage of tablets were sold without the warranty?

(c) What percentage of tablets purchased with cash were sold with the warranty?

(d) What percentage of tablets sold with the warranty were purchased with cash?

(e) What percentage of all tablets sold were purchased with cash and without a warranty?

(f) Are paying with cash and buying the warranty indepdendent events? Why or why not?

(g) Suppose you build a box model to describe the situation above and chose two tickets with replacement. What is the chance that both draws are tickets where the tablet was purchased with cash?

4. Suppose you can somehow choose two people at random who took the SAT in 2014. Scores were Normally distributed with mean and stanard deviation of 1497 and 322, respectively. What is the probability that both of them scored above a 1520? Assume that the scores of the two test takers are independent.