Question

Payment types vary at the grocery store. Here are the proportions of the leading three payment methods: Payment Method Cash Credit Cards Debit Cards Proportion 0.11 0.43 0.21 If a transaction is selected at random, the probability that the customer did not pay with a Debit Card is .

Answer 1

0.79

Explanation:

Given the probability distribution :

Payment Methd: Cash Credit Cards Debit Cards Proportion : ____0.11 ____ 0.43 _____0.21

The probability that a customer did not pay with debit card can be obtained as :

If customer did not pay with debit card, then he would have paid with any of the other payment methods

This Can best be obtained using the complement method

P(not debit card) = 1 - P(debit card)

P(debit card) = 0.21

P(not debit card) = 1 - 0.21

P(not debit card) = 0.79