Question

For this activity, you will be creating a confidence interval for the average number of hours of TV watched. Last semester, my MAT 152 online students asked the question, “How many hours of screen time do you have in a typical week?” Please use the data they collected to answer the following questions. Data: 21, 2, 28, 30, 18, 21, 25, 20, 25, 14, 21, 25, 50, 39, 46, 20, 35, 45, 37, 46 Are there any outliers in this data set? What calculator test (1-PropZInt, Z-Interval, or T-Interval), Excel, or StatCrunch function will you use to find the confidence interval? Why do you use this test (and not one of the other 2 tests)?

Here is the full question:

lease use the skills you learned in section 9.2 for this assignment.

For this activity, you will be creating a confidence interval for the average number of hours of TV watched. Last semester, my MAT 152 online students asked the question, “How many hours of screen time do you have in a typical week?” Please use the data they collected to answer the following questions.

Data: 21, 2, 28, 30, 18, 21, 25, 20, 25, 14, 21, 25, 50, 39, 46, 20, 35, 45, 37, 46

1. Are there any outliers in this data set?
2. What calculator test (1-PropZInt, Z-Interval, or T-Interval), Excel, or StatCrunch function will you use to find the confidence interval?
3. Why do you use this test (and not one of the other 2 tests)?
4. Using a 95% confidence level, what is the confidence interval?
5. What is the point estimate for the population mean?
6. What is the margin of error?
7. Suppose you knew the standard deviation for all Americans' screen time was 4 hours. If you wanted your results to be within a margin of error of 0.25 hours, how many people would you have to survey (use a 95% confidence level)?
8. Name at least 2 ways this data could be biased and hence the confidence interval would not be a good estimate of the population mean.

Your final write-up should number (1-8) your answers to each question as well as an explanation of how you arrived at the answers. For example, please include what calculator functions or computations you are using to arrive at the confidence interval.

Answer 1

Variable	Hours
n	20
Mean	28.4
StDev	12.45
Minimum	2
Q1	20.25
Median	25
Q3	38.5
Maximum	50
IQR	18.25
Lower Whisker	-7.125
Upper Whisker	55.775

1. Are there any outliers in this data set?

Ans: All the data values fall within the interval of Lower Whisker and Upper Whisker. Hence, there are not any outliers in this data set.

2. What calculator test (1-PropZInt, Z-Interval, or T-Interval), Excel, or StatCrunch function will you use to find the confidence interval?

Ans: For calculation of T-interval in Excel is used to find the confidence interval.

3. Why do you use this test (and not one of the other 2 tests)

Ans: We use a 2-tail test.

4. Using a 95% confidence level, what is the confidence interval?

Ans: The 95% Confidence interval is