Description
Question 1
1 Point
Open StatKey and choose One Quantitative Variable. Select the variable STUDENT SURVEY(Exercise Hours). Find the mean, standard deviation, and sample size.
The mean hours is Blank 1 and the standard deviation is Blank 2.
The sample size is Blank 3
Blank 1
Blank 2
Blank 3
Question 2
1 Point
Refer to #1: What critical value would we use to compute the margin of error for a 90% confidence interval in this case?Integer, decimal, or E notation allowed
Question 3
2 Points
Use the summary statistics you identified in #1 and the critical value from #2 to compute the margin of error and then determine the bounds for a 90% confidence interval for the mean hours of exercise for all students.
The margin of error is Blank 1 (Round to 3 decimal places)
The lower bound is Blank 2 and the upper bound is Blank 3. (Enter the bounds to 3 decimal places)
Blank 1
Blank 2
Blank 3
Question 4
2 Points
In StatKey select One Quantitative Variable and open the April 14 Temp-2e (San Fran) dataset (There should be 21 observations).
The sample mean is Blank 1 and the sample standard deviation is Blank 2
To compute a 95% confidence interval for the mean April temperature in San Francisco, the critical value would be Blank 3
Blank 1
Blank 2
Blank 3
Question 5
2 Points
Refer to Question 4. Use the summary statistics and critical value you determine to compute a 95% confidence interval for the mean April temperatures in San Francisco.
The lower bound is Blank 1 and the upper bound is Blank 2 (Round the margin of error to 3 decimal places before computing each bound)
Blank 1
Blank 2
Question 6
1 Point
Open StatKey and choose One Categorical Variable. Select the variable Nutrition Study (Vitamin Use).
The sample size was Blank 1
The proportion of respondents who regularly use vitamins is Blank 2
Blank 1
Blank 2
Question 7
1 Point
Refer to Question 6. If we wanted to compute a 99% confidence interval for the proportion of adults who use vitamins regularly, we would need to use what critical value?
The critical value is Blank 1
Blank 1
Question 8
2 Points
Refer to questions 6 & 7: Determine a 99% confidence interval for the proportion of adults who use vitamins regularly. (Do not round the sample proportion given in Statkey in your calculations)
The margin of error is Blank 1 (round to 3 decimal places)
The lower bound is Blank 2 and the upper bound is Blank 3 (give your answer to 3 decimal places)
Blank 1
Blank 2
Blank 3
Question 9
1 Point
If we decrease the confidence level for the interval calculated in Question 8 to 95% what would happen to the margin of error?
It would stay the same.
It would get larger.
It would get smaller.
Question 10
1 Point
Suppose the results for the vitamin study were based on a sample of 700 adults. Assuming the sample proportion remains the same, how would the margin of error for your interval change?
It would stay the same.
It would get larger.
It would get smaller
Question 11
1 Point
Suppose you want to estimate the proportion of adults who use vitamins regularly with a 95% confidence interval and a margin of error of 3%. Assuming the sample proportion is about 0.40, what sample size would you need?
The required sample size is Blank 1
Blank 1
Question 12
1 Point
Refer back to Q1. Suppose you want to estimate the mean number of exercise hours within 0.5 hours using a 90% confidence interval, what sample size would you need? (You can use the standard deviation from Q1)
The required sample size is Blank 1
Blank 1
