# If the level of confidence and sample size remain the same, a

1. If the level of confidence and sample size remain the same, a confidence interval for a population proportion p will be narrower when p(1-p) is larger than when it is smaller.

True

False

2. The standard deviation of the sampling distribution of the sample mean is the same as the population standard deviation.

True

False

3. If a population is known to be normally distributed, then it follows that the sample standard deviation must equal population standard deviation.

True

False

4. The following results were obtained from a simple regression analysis:

Y-hat =37.2895-(1.2024)X

R2= .6744 sb(1) = .2934

When X (independent variable) is equal to zero, the estimated value of Y (dependent variable) is equal to:

a. 37.2895

b. -1.2024

c. .6774

d. .2934

5. In a two tailed test if the p value is less than the significance level alpha, then:

a. H0 is rejected

b. H0 is not rejected

c. H0 may or may not be rejected depending on the sample size n

d. Additional information is needed and no conclusion can be reached about whether H0 should be rejected

6. The width of a confidence interval will be:

a. Narrower for 99% confidence than for 90% confidence

b. Wider for a sample size of 64 than for a sample size of 36

c. Wider for a 99% confidence than for 95% confidence

d. Narrower for sample size of 25 than for a sample size of 36

e. None of the above

7. The following results were obtained from a simple regression analysis:

Y-hat =37.2895-(1.2024)X

R2= .6744 sb(1) = .2934

For each unit change in X (independent variable), the estimated change in Y (dependent variable) is equal to:

a. 37.2895

b. -1.2024

c. .6744

d. .2934

8. If we have a sample size of 100 and the estimate of the population proportion is .10, the standard deviation of the sampling distribution of the sample proportion is:

a. 0.0009

b. 0.03

c. 0.3

d. 0.01

e. 0.10

9. The population of all sample proportions has a normal distribution if the sample size (n) is sufficiently large. A rule of thumb for ensuring that n is sufficiently large is:

a. np >= 10

b. n(1–p)>= 10

c. np(1-p) ≤ 10

d. n(1–p) ≤10 and np ≤ 10

e. np >= 10 and n(1–p) >= 10

10.

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