Question

"Cyber Monday is a huge online shopping day. In 2017, approximately 21% of Cyber Monday shoppers used their mobile device to make a purchase. If a person used a mobile device to make a purchase, the probability of making a purchase from Amazon was .55. Suppose a Cyber Monday purchase is selected at random. What is the probability that the purchase was made with a mobile device and was from Amazon."

Answer 1

11.55% probability that the purchase was made with a mobile device and was from Amazon.

Explanation:

We have these following probabilities:

21% probability that a Cyber Monday shopper used their mobile device to make a purchase.

55% probability that a purchase made with a mobile device is from Amazon.

What is the probability that the purchase was made with a mobile device and was from Amazon."

55% of 21%

So

P = 0.21*0.55 = 0.1155

11.55% probability that the purchase was made with a mobile device and was from Amazon.