10 Questions

Questions and Answers

- 1.Estimate the critical value of t for a 98% confidence interval with df = 20
- A.
2.528

- B.
2.518

- C.
1.325

- D.
2.539

- E.
2.330

- 2.Find the P-value for |t| > 1.76 with 24 degrees of freedom.
- A.
.0911

- B.
.0456

- C.
.1562

- D.
.9544

- E.
.0781

- 3.You want to estimate the average gas price in your city for a gallon of regular gas. From your sample of 15 gas stations, you calculate a 95% confidence interval of ($1.98, $2.16). Interpret the confidence interval.
- A.
You are 95% sure that the average price for a gallon of gas in your city is between $1.98 and $2.16.

- B.
If you took many samples of gas stations in your city, about 95% of them would produce this confidence interval.

- C.
95% of all samples of gas stations will have average costs between $1.98 and $2.16.

- D.
You are 95% sure that gas stations in this sample have average costs between $1.98 and $2.16.

- E.
You are 95% confident that the average price for a gallon of gas in the country is within $0.09 of $2.07.

- 4.
**A confidence interval estimate is determined from the**GPAs of a simple random sample of*n*students. All other things being equal, which of the following will result in a smaller margin of error?- A.
A smaller confidence level

- B.
A larger sample standard deviation

- C.
A smaller sample size

- D.
A larger population size

- E.
A smaller sample mean

- 5.
**In an SRS of 80 teenagers, the average number of texts handled in a day was 50 with a standard deviation of 15. What is the 96% confidence interval for the average number of texts handled by teens daily?**- A.
- B.
- C.
- D.
- E.

- 6.
**The number of accidents per day at a large factory is noted for each of 64 days with mean of 3.58 and standard deviation of 1.52. With that degree of confidence we can assert that the mean number of accidents per day at the factory is between 3.20 and 3.96.**- A.
95%

- B.
48%

- C.
63%

- D.
90%

- E.
99%

- 7.
- A.
1. I 2. II

- B.
1. I 2. I

- C.
1. II 2. I

- D.
1. II 2. II

- E.
More information is needed to answer these questions

- 8.
- A.
No, because the p-value is greater than .10

- B.
Yes, the p-value is between .01 and .05 indicating some evidence for the teacher's belief.

- C.
Yes, the p-value is between .001 and .01 indicating strong evidence for the teacher's belief.

- D.
Yes, the p-value is between .05 and .10 indicating strong evidence for the teacher's belief.

- E.
Yes, the p-value is less than .001 indicating strong evidence for the teacher's belief.

- 9.
**Thirty students volunteer to test which of two strategies for taking multiple-choice exams leads to higher average results. Each student flips a coin, and if heads, uses Strategy A on the first exam and then Strategy B on the second exam, while if tails, uses Strategy B first and then Strategy A. The average of all 30 Strategy A results is then compared to the average of all 30 Strategy B results. What is the conclusion at the 5% significance level if a two-sample hypothesis test, , results in a p-value of .18?**- A.
The observed difference in average scores is significant.

- B.
The observed difference in average scores is not significant.

- C.
A conclusion is not possible without knowing the average scores resulting from using each strategy.

- D.
A conclusion is not possible without knowing the averages scores and the standard deviations resulting from using each strategy.

- E.
A two-sample hypothesis test should not be used here.

- 10.
- A.
1.55

- B.
1.22

- C.
2.22

- D.
1.88

- E.
2.66