Question

A.

For the following distribution,

X	P(x)
0	0.130
1	0.310
2	0.350
3	0.190
4	0.020

What is the mean of the distribution?

A. 0.890

B. 1.660

C. 0.480

D. 1.042

B.

For a binomial distribution, the mean is 0.6 and n = 2. What is π for this distribution?

A. 2.6

B. 0.3

C. 5.0

D. 1.3

C.

For a binomial distribution, the mean is 5.0 and n = 5. What is π for this distribution?

A. 0.5

B. 1.0

C. 0.8

D.2.0

D.

For a standard normal distribution, what is the probability that z is greater than 1.75?

A. 0.0684

B. 0.0401

C. 0.0456

D. 0.0912

E.

The mean of a normally distributed group of weekly incomes of a large group of executives is $1,262 and the standard deviation is $108. What is the z-score for an income of $1,533?

A. 2.51

B. 0.50

C. 2.00

D. 10.00

Answer 1

a) From the given data

X	P(X=x)	xP(X=x)
0	0.13	0
1	0.31	0.31
2	0.35	0.7
3	0.19	0.57
4	0.02	0.08
Total:	1	1.66

Mean = 1.66

Correct Answer: Option (B) 1.66

2. Given mean = 0.6 and n =2
In binomial distribution mean = np
0.6 = np
0.6 = 2*p
p = 0.6/2 = 0.3

Correct Answer: Option (B) 0.3

3. Given mean = 5 and n = 5
In binomial distribution mean = np
5 = np
5 = 5*p
p = 5/5 = 1

Correct Answer: Option (B) 1

4.  Correct Answer: Option (B) 0.0401

The probability that z is greater than 1.75 is 0.0401

5. Z-Score = ($1,533 - $1,262) / $108 = 2.51

Correct Answer: Option (A) 2.51