A hair solon did a survey of 360 customers regarding satisfa

A hair solon did a survey of 360 customers regarding satisfaction with service and type of customer. A walk-in customer is one who has seen no ads and not been referred. The other customers either saw a TV ad or were referred to the salon, (but not both) Assume the sample represents the entire population of customers. Find the probability that a customer is Not satisfied Not satisfied and walk-in Not satisfied, given referred Very satisfied Very satisfied, given referred Very satisfied and TV ad Are the events satisfied and referred independent or not?

Solution

a)

P(not satisfied) = 35/360 = 0.097222222

b)

P(not satisfied and walk in) = 21/360 = 0.058333333

c)

P(not satisfied|referred) = 5/149 = 0.033557047

d)

P(VS) = 107/360 = 0.297222222

e)

P(VS|R) = 48/149 = 0.322147651

f)

P(VS n TV) = 31/360 = 0.086111111

g)

If they are independent, then P(S) = P(S|R).

P(S) = 138/360 = 0.383333333

P(S|R) = 59/149 = 0.395973154

As they are not equal [although close], they are not independent.