q1. the point estimate of the variance in a regression model is:

a. b(1)

b. SSE

c. b(0)

d. SSR/df

e. MSE

q2. If the level of confidence and sample size remain the same, a confidence interval for a population proportion p will be wider than p(1-p) is larger than when it is smaller.

True or False

q3. The level of significance indicates the probability of rejecting a false null hypothesis

True or False

q4. If two events A and B are not mutually exclusive and not independent, then the probability of their union P(A or B) is:

a. the sum of the two individual probabilities less the joint probability of A and B

b. the sum of the two individual probabilities P(A) and P(B)

c. P(A or B)= P(A) + P(B) - P(A)*P(B)

d. the product of the two individual probabilities P(A) and P(B)

q5. the mean of the binomial distribution is equal to:

a. p

b. np(1-p)

c. square root of np(1-p)

d. p^x(1-p)^(n-x)

e. np

q6. In a study conducted for the State Department of Education, 30% of the teachers who left teaching did so because they were laid off. Assume that we randomly select 10 teachers who have recently left their profession. Find the probability that exactly 4 of them were laid off.

a. 0.2001

b. 0.2668

c. 0.3000

d. 0.0090

q7. The average customer waiting time at a fast food restaurant has been 7.5 minutes. The customer waiting time has a normal distribution. The manager claims that the use of a new system will decrease average customer waiting time in the store. What is the null and alternative hypothesis for this scenario?

a. H0: 7.5 and H1: < 7.5

b. H0: = 7.5 and H1: 7.5

c. H0: < 7.5 and H1: 7.5

d. H0: 7.5 and H1: > 7.5

e. H0: > 7.5 and H1: 7.5

q8. The following results were obtained form a simple regression analysis:

Y-hat = 37.2895 - (1.2024)X

R^2= 0.6744 sb(1) = 0.2934

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

a. 0

b. 37.2895

c. -1.2024

d. 0.2934

e. 0.6774

q9. The following results were obtained form a simple regression analysis:

Y-hat = 37.2895 - (1.2024)X

R^2= 0.6744 sb(1) = 0.2934

When X increases by 1 unit, Y will change by

a. -1.2024

b. 0.2934

c. 37.2895

d. 0.6744

e. none of the above

q10. If a one sided null hypothesis for a single mean cannot be rejected at a given significance level, then the corresponding two-sided null hypothesis (same sample size, the same standard deviation, the same mean) will ________________be rejected at the same significance.

a. always

b. sometimes

c. never