Hi, I need some help with this question.(adsbygoogle = window.adsbygoogle || []).push({});

Seventy percent of all Big Burger chain stores decided to advertise in their local newspapers. Of those chain stores that advertised in their local newspapers, 60% had an increase in sales. Of those chain stores that did not advertise in their local newspapers, 25% had an increase in sales.

(a) What is the probability that a randomly selected store has an increase in sales.

(b) What is the probability that a randomly selected store with an increase in sales advertised in its local newspaper?

for a)

I did

(.7)(.6) + (.3)(.25) = 0.495

for b)

A = Increased sales

B = Advertised

P(A|B) = 0.495/0.7 = 0.707

Did I do this right?

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# Probablity Question

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