1) Suppose the mean width of car seat covers used by Italian car manufacture is 15 inches with the standard deviation 9. A random sample of 36 covers is drawn from this population. What are the standard normal z-value and the probability that the sample average width is more than 14 inches?

a)-2 and 0.9772

b) 2 and 0.0228

c) 0.6667 and 0.7486

d) 12 and 0.6293

2) "The time it takes to complete the assembly of an Aircraft is normally distributed with a standard deviation of 45 days. If we randomly select 20 Aircraft, what is the probability that the standard deviation for the time of assembly of these units is less than 30 days?"

a) <0.055

b) <0.025

c) <0.045

d) <0.034

3) "If x = 4 , population mean = 5.6 and population standard deviation = 6.5 , the corresponding z value will be "

a) -0.2461

b) 0.2461

c) -0.5

d) answer not given

4) In hypergeometric experiments trials are?

a) independent

b) dependent

c) simultaneous

d) not applicable

5) If Ha is written as mean of population 1 is not equal to mean of population

a) it is two tail test

b) one tail test

c) no tail test

d) None of the above

6)A small voting district has 101 female voters and 95 male voters. Arandom sampleof 10 voters is drawn. What is the probability exactly 7 of the voters will be female?

a) 0.75

b) 0.51

c) 0.224

d) 0.13

7) In a standard normal distribution the probability given in the table corresponding the z value -2.00 is

a) 0.0228

b) 0.0238

c) 0.0428

d) answer not given

8) Error margin is obtained by

a) adding error to mean

b) subtracting error from mean

c) adding and subtracting error from mean

d) not considering error

9) " If the variance of X is equals 25 and the sample size n=6, the population variance is: "

a) 33

b) 45

c) 150

d) 23