Complete the mcq:
1. A sample of 49 households is taken from a population in which the standard deviation is 7. The standard error of the mean is:
a. 0.142
b. 1
c. 7
d. 18.5
2. It is desired to construct a 95% confidence interval. The correct value of Z to obtain for the 95% confidence interval is:
a. 2.06
b. 2.58
c. 1.96
d. 2.33
3. A confidence interval has been constructed with total width of 50 units. If the sample mean is 100, the lower bound of the interval is
a. 0
b. 25
c. 50
d. 75
4. Hogan Company has constructed a new assembly line for mixing paint of various colors and consistencies. A recent sample of 200 one-gallon cans yielded that 2 were improperly mixed. What sample size is required in order to construct a 95% confidence interval (z = 1.96) in the next study and get to within +/- 0.5% of the true percentage of defective cans of paint being assembled?
a. 78 cans
b. 152 cans
c. 777 cans
d. 1522 cans
5. The management of Fast Airlines tracks the proportion of the company's passengers that are flying on business trips. An on-board preliminary study conducted last year revealed that 34% of the passengers were involved in a business venture. What sample size is required in order to construct a 95% confidence interval (z = 1.96) in the next study and get to within +/- 1% of the true percentage of business flyers?
a. 8621 passengers
b. 4399 passengers
c. 862 passengers
d. 440 passengers