Question

Albertsons conducted a one-question customer survey of customers selected at random to evaluate satisfaction with length of time waiting to check out. The survey has six possible responses, and a customer choses exactly one response. The following table is the probability distribution based on the results of the survey.

Response	Probability
Very satisfied	0.11
Somewhat satisfied	0.36
Neither satisfied nor dissatisfied	0.1
Somewhat dissatisfied	0.05
Very dissatisfied	.05
Declined to respond

Define the following events:

A = {customer is very satisfied}

B = {customer is somewhat satisfied}

C = {customer is neither satisfied nor dissatisfied}

What is the probability P(A or B or C)?

Express your answer in decimal form to 3 decimal places.

Answer 1

Given:

The probability distribution based on the results of the survey is

Response	Probability
Very satisfied	0.11
Somewhat satisfied	0.36
Neither satisfied nor dissatisfied	0.1
Somewhat dissatisfied	0.05
Very dissatisfied	.05
Declined to respond

Define the following events:

A = {customer is very satisfied}

B = {customer is somewhat satisfied}

C = {customer is neither satisfied nor dissatisfied}

P(A) = 0.11

P(B) = 0.36

P(C) = 0.10

The events A, B and C are independent events.

If A , B and C are independent events then

P(A or B or C) = P(A) + P(B) + P(c)

= 0.11 + 0.36 + 0.10

= 0.57

Therefore the probability P(A or B or C) is 0.570