Question

A department store manager has monitored the number of complaints received per week about poor service. The probabilities for numbers of complaints in a week, established by this review, are shown in the table.

Number of complaints	0	1	2	3	4	5
Probability	0.20	0.29	0.26	0.12	0.05	0.08

What is the probability of between 1 and 3 (inclusive) complaints received per week?

Please specify your answer in decimal terms and round your answer to the nearest hundredth (e.g., enter 12 percent as 0.12).

Note that the correct answer will be evaluated based on the full-precision result you would obtain using Excel.

3. A department store manager has monitored the number of complaints received per week about poor service. The probabilities for numbers of complaints in a week, established by this review, are shown in the table.

Number of complaints	0	1	2	3	4	5
Probability	0.13	0.21	0.44	0.07	0.06	0.09

What is the mean of complaints received per week?

Please round your answer to the nearest hundredth.

Note that the correct answer will be evaluated based on the full-precision result you would obtain using Excel.

4. Let X be a discrete random variable. If Pr(X<9) = 3/8, and Pr(X<=9) = 7/16, then what is Pr(X=9)?

Please specify your answer in decimal terms and round your answer to the nearest hundredth (e.g., enter 12 percent as 0.12).

Answer 1

2. Let X be the numbers of complaints in a week. The probabilities for numbers of complaints in a week, established by this review, are

Number of complaints (x)	Probability- P(x)
0	0.2
1	0.29
2	0.26
3	0.12
4	0.05
5	0.08

the probability of between 1 and 3 (inclusive) complaints received per week is

ans: the probability of between 1 and 3 (inclusive) complaints received per week is 0.67

3. Let X be the numbers of complaints in a week. The probabilities for numbers of complaints in a week, established by this review, are

Number of complaints (x)	Probability- P(x)
0	0.13
1	0.21
2	0.44
3	0.07
4	0.06
5	0.09

The expected value of X is the mean of complaints received per week.

The expected value of X is

ans: the mean of complaints received per week is 1.99

4.Let X be a discrete random variable.

If Pr(X<9) = 3/8, and Pr(X<=9) = 7/16, t

We know that we can write P(X<=9) as

ans:  Pr(X=9) is 0.06 (rounded to 2 decimals)