Question

John runs a computer software store. Yesterday he counted 125 people who walked by the store, 58 of whom came into the store. Of the 58, only 21 bought something in the store. (Round your answers to two decimal places.)

(a) Estimate the probability that a person who walks by the store will enter the store.
(b) Estimate the probability that a person who walks into the store will buy something.
(c) Estimate the probability that a person who walks by the store will come in and buy something.
(d) Estimate the probability that a person who comes into the store will buy nothing.

Answer 1

a) 0.46 = 46% probability that a person who walks by the store will enter the store.

b) 0.36 = 36% probability that a person who walks into the store will buy something.

c) 0.17 = 17% probability that a person who walks by the store will come in and buy something.

d) 0.64 = 64% probability that a person who comes into the store will buy nothing.

Explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

(a) Estimate the probability that a person who walks by the store will enter the store.

58 out of 125. So

`p = (58)/(125) = 0.46`

0.46 = 46% probability that a person who walks by the store will enter the store.

(b) Estimate the probability that a person who walks into the store will buy something.

58 walked, 21 bought. So

`p = (21)/(58) = 0.36`

0.36 = 36% probability that a person who walks into the store will buy something.

(c) Estimate the probability that a person who walks by the store will come in and buy something.

21 came in and bought out of 125 that walked by. So

`p = (21)/(125) = 0.17`

0.17 = 17% probability that a person who walks by the store will come in and buy something.

(d) Estimate the probability that a person who comes into the store will buy nothing.

0.36 probability that a person buys something, so 1 - 0.36 = 0.64 = 64% probability that a person who comes into the store will buy nothing.