Q1. The width of a confidence interval will be:
A. Narrower for 95% confidence than 99% confidence
B. Wider for a sample size of 100 than for a sample size of 50
C. Wider for 90% confidence than 95% confidence
D. Narrower when the sample standard deviation (s) is large than when s is small
Q2. When the level of confidence and sample size remain the same, a confidence interval for a population proportion p will be __________ when p(1-p) is larger than when p(1-p) is smaller.
A. Narrower
B. Wider
C. Neither A nor B, they will be the same
D. Cannot tell from the information given
Q3. A confidence interval increases in width as
A. The level of confidence increases
B. n decreases
C. s increases
D. All of the above
E. None of the above
Q4. In a manufacturing process a random sample of 9 bolts manufactured has a mean length of 3 inches with a standard deviation of .3 inches. What is the 95% confidence interval for the true mean length of the bolt?
A. 2.804 to 3.196
B. 2.308 to 3.692
C. 2.769 to 3.231
D. 2.412 to 3.588
E. 2.814 to 3.186