Question

In the town of Maplewood a certain type of DVD player is sold at just two stores, 43% of the sales 13) are from store A and 57% of the sales are from store B. 2.4% of the DVD players sold at store A are defective while 4.0% of the DVD players sold at store B are defective. If Kate receives one of these DVD players as a gift and finds that it is defective, what is the probability that it came from store A?
A) 0.312
B) 0.453
C) 0.688
D) 0.024

Answer 1

Answer:

Option A 0.312 is right

Step-by-step explanation:

Given that iN Maplewood a certain type of DVD player is sold at just two stores, 43% of the sales 13) are from store A and 57% of the sales are from store B. 2.4% of the DVD players sold at store A are defective while 4.0% of the DVD players sold at store B are defective.

Prob for any random item form store to be defective = Prob from A and defective +Prob from B and defective

=$0.43(0.024)+0.57(0.04)\\=0.03312$

Prob it came from A and defective = 0.$0.43(0.024)=0.01032$

If Kate receives one of these DVD players as a gift and finds that it is defective, what is the probability that it came from store A

=$\frac{0.01032}{0.03312} \\=0.312$