In: Statistics and Probability
Statistic Question
Market research for an online electronics retailer showed that 23% of its customers purchased a smartphone. 12% of these smartphone customers used an online payment system (such as Paypal) to pay for their purchases, i.e., given that a customer purchased a smartphone, the probability was 12% that he/she used an online payment system to pay. In general, 8% of the customers used an online payment system to pay for their purchases.
a.What percent of customers did not purchase a smartphone?
b.What percent of customers purchased a smartphone and used an online payment system to pay?
c.What percent of customers purchased a smartphone or used an online payment system to pay?
d.Are the events “purchased a smartphone” and “used an online payment system to pay” mutually exclusive? Why or why not?
e.Are the events “purchased a smartphone” and “used an online payment system to pay” independent? Use probabilities to justify your answer.
Solution: a.What percent of customers did not purchase a smartphone?
Answer: %
b.What percent of customers purchased a smartphone and used an online payment system to pay?
Answer: We are given that 23% of customers purchased online and of these 23% of customers 12% paid online.
Therefore the percent of customers purchased a smartphone and used an online payment system to pay is %
c.What percent of customers purchased a smartphone or used an online payment system to pay?
Answer: Let X be the probability that a customer purchased a smartphone and is given by:
and Let Y be the probability that a customer used an online payment system to pay and is given below:
Therefore the percent of customers purchased a smartphone or used an online payment system to pay is 28.24%
d.Are the events “purchased a smartphone” and “used an online payment system to pay” mutually exclusive? Why or why not?
Answer: The events Purchasing a smartphone and making an online payment aren't mutually exclusive, because we could have purchased a smartphone and paid online.
e.Are the events “purchased a smartphone” and “used an online payment system to pay” independent? Use probabilities to justify your answer.
Answer: Purchased a smartphone and used an online payment system can be independent only if
We know that
Since , therefore the events "purchased a smartphone" and "used an online payment system to pay" are not independent.