Week 4 Project – STAT 3001
Student Name: <Type your name here>
Date: <Enter the date on which you began working on this assignment.>
Instructions: To complete this project, you will need the following materials:
· Statdisk User’s Manual (link found on week 4 Project resources page)
· Access to the Internet to download the Statdisk program.
· You don’t have to explain your steps unless the problem specifically says to.
Part I. Analyze Data
Instructions
Answers
1. Open the file GARBGE WEIGHTS using menu option Datasets and then Elementary Stats, 13th Edition. This file contains some information about the weights of different materials placed in the garbage per household per week. How many observations are there in this file?
2. Would you expect to find more paper, plastic, or glass in the garbage by weight?
Part II. Descriptive Statistics
3-6 Generate descriptive statistics for paper, plastic, and glass and complete the following table. Round all results to 3 decimal places.
Variable
Sample
Mean
Sample
Standard Deviation
Sample Size
Paper
Plastic
Glass
7. Did you get the results you expected here? Explain why.
8. In which of the three groups did we experience the MOST variation?
Part III. Confidence Intervals
9. Generate a 95% interval for the mean of the PAPER group. Paste your results here.
10. Generate a 95% interval for the mean of the PLASTIC group. Paste your results here.
11. Generate a 95% interval for the mean of the GLASS group. Paste your results here
12. Create a graph below by illustrating all three confidence intervals on one graph using the tools in your word processor (example below). Statdisk cannot do this for you. Create your graph and turn the font red. For this process, I just used the dashes and wrote a scale below the axes.
Here is an example, but it is not based on the data you are analyzing:
Case 1 14———————42
Case 2 35————————-70
________________________________________
0 20 40 60
Your Solution:
13. Based on the confidence intervals shown above, what conclusion can you draw about the weight of the different types of garbage?
Part IV. Hypothesis Testing
14. For planning purposes, the landfill in Mountainview estimates the weight of plastic to be 1.7 pounds per household each week. You have noticed a lot of plastics in the garbage in your neighborhood and want to test the claim that the weight of plastic is more than 1.7 pounds.
Step 1. Determine parameter of interest and compose null and alternative hypotheses.
Step 2. Determine the sample mean, sample standard deviation, and sample size. [Hint: You recorded these previously in Part II, #3-6]
Step 3. Determine the likelihood that the population mean is actually equal to 1.7 by completing a Hypothesis Test: One Mean in STATDISK. Use significance of 0.05. Paste your results here. Remember that the pulldown menu in Statdisk must match the alternative hypothesis statement.
Step 4. State your conclusion. The conclusion statement has a prescribed format: it should include a comparison of the p-value and alpha, whether you reject or support the null hypothesis, and a paraphrase of the hypothesis supported by the data.
15. For your second hypothesis test, the landfill states that the weight of glass is 4.8 pounds per week per household. You see that most families are recycling their glass so you claim that the weight of glass in the garbage is less than 4.8 pounds.
Step 1. Determine parameter of interest and compose null and alternative hypotheses.
Step 2. Determine the sample mean, sample standard deviation, and sample size. [Hint: You recorded these previously in Part II, #3-6]
Step 3. Determine the likelihood that the population mean is actually equal to 4.8 by completing a Hypothesis Test: One Mean in STATDISK. Use significance of 0.01. Paste results here. Remember that the pulldown menu in Statdisk must match the alternative hypothesis statement.
Step 4. State your conclusion. The conclusion statement has a prescribed format: it should include a comparison of the p-value and alpha, whether you reject or support the null hypothesis, and a paraphrase of the hypothesis supported by the data.
16. Answer the following questions based on the above hypothesis test.
a. What is the p-value for the hypothesis test in #15 and what does it represent?
b. Given that your data, hypotheses, and p-value do not change, what would need to be different in order for you to FAIL TO REJECT the null hypothesis here? (What do you compare to make your rejection decision?)
Submit your final draft of your Word file by going to Week 4, Project, and follow the directions under Week 4 Assignment 2Please use the naming convention “WK4Assgn2+last name + first initial” as the Submission Title.
