Carmen Homework 12

Your friend claims the average price of a burger in the Columbus Gateway Area is $10.00. You believe it's lower than that. What symbol represents the $10 in this scenario?

a. MU of X b. MU of O c. X-bar

If everything else stays the same, a 90% confidence interval is narrower than a 95% confidence interval.

a. True b. False

The margin of error of a confidence interval increases if the population has a higher standard deviation.

a. True b. False

The p-value will change if you get a new data set.

a. True b. False

The value of the significance level(alpha) will change if you get a new data set.

a. True b. False

If your 95% confidence interval for the average gas price in Columbus Ohio turned out to be ($2.25, $2.75), do you know what the sample mean was?

a. Yes b. No

Answer Sheet

1. b 2. b 3. a 4. a 5. c 6. b 7. a 8. b 9. a 10. b

Which of the following would increase the Margin of Error>

a. Decrease the standard deviation b. Increase the confidence c. Increase the sample size

Suppose someone claims the average delivery time for u.S. packages to be delivered during December is 2 days. You believe it takes longer than that. You conduct a hypothesis test; what are your hypotheses?

a. Ho: X-bar = 2 vs. Ha: X-bar > 2 b. Ho: Mu = 2 vs. Ha: Mu > 2 c. Ho: X-bar = 2 vs Ha: X-bar != 2 d. Ho: Mu > 2 vs. Ha: Mu <= 2

When you are asked to provide a range of likely values for the average gas price in Columbus Ohio, what technique do you use?

a. Hypothesis test for the population mean b. Confidence interval for the population mean c. Hypothesis test for the sample mean d. Confidence interval for the sample mean

Suppose you found a 95% confidence interval for the mean using a random sample size of n, and you found it was too wide; that is, the margin of error was too large. If you wanted the margin of error to be 1/4 of what it was before, what do you have to do to the sample size?

a. Increase it by 4 times what it was before b. Decrease it by 1/4 of what it was before c. Increase it by 16 times what it was before d. None of the above