PH 7B Public Health Statistics IIHomework 2
Question 1 (5pts): A community in Irvine has installed several radar detectors to address the
speeding problems. Ever since that, no one has exceeded the speed limit. This is a
phenomenon of:
A. Regression effect
B. Regression fallacy
C. Simpson’s paradox
D. None of the above
Explain:
Question 2 (5pts): The following results were obtained in a study of about 2,000 families:
average height of mother= 63 inches, SD=2.5 inches. Average height of daughter= 65 inches,
SD=4.0 inches. r= 0.25. What is the predicted height of a daughter when the height of her
mother is 68 inches?
A. 62 inches
B. 64 inches
C. 66 inches
D. 67 inches
Show your work:
Question 3 (5pts). IQ scores are scaled to have an average of about 110, and an SD of about
10, both for men and for women. The correlation between the IQs of husbands and wives is
about 0.6. A large study of families found that the men whose IQ was 130 had wives whose IQ
averaged 122. For the wives whose IQ was 122, the average IQ of their husbands are:
A. Between 130 and 140
B. 130
C. Between 120 and 130
D. Below 120
Explain:
PH 7B Public Health Statistics II
Homework 2
Question 4 (20 pts). Two regression models are fitted to a small data set using different
statistical approaches (eg. simple or multiple linear regression). For each subject, the table
shows the actual value of y and the predicted value from the regression line. (use n=5, keep 2
decimal places)
Model 1
Model 2
Actual value of y
Predicted value of y
Actual value of y
Predicted value
of y
54
74
54
64
35
15
35
55
76
86
76
56
27
17
27
76
18
57
18
48
1) Compute the r.m.s for each model, show your work.
2) Which model do you prefer to predict y? Explain.
PH 7B Public Health Statistics II
Homework 2
Question 5 (15 pts). A study has recruited 100 children in Orange County and collected data
on their height at age 6 years old and age 10 years old (the scatter diagram is football-shaped):
Average height at 6 = 126 cm SD=5cm
Average height at 10 = 146 cm SD=4cm, r=0.60
1) Find the r.m.s error for the regression prediction of height at 10 years old from height at
6 years old. Show your work and interpret your results.
2) Find the r.m.s error for the regression prediction of height at 6 years old from height at
10 years old. Show your work and interpret your results.
3) Which model has better performance?
Why Work with Us
Top Quality and Well-Researched Papers
We always make sure that writers follow all your instructions precisely. You can choose your academic level: high school, college/university or professional, and we will assign a writer who has a respective degree.
Professional and Experienced Academic Writers
We have a team of professional writers with experience in academic and business writing. Many are native speakers and able to perform any task for which you need help.
Free Unlimited Revisions
If you think we missed something, send your order for a free revision. You have 10 days to submit the order for review after you have received the final document. You can do this yourself after logging into your personal account or by contacting our support.
Prompt Delivery and 100% Money-Back-Guarantee
All papers are always delivered on time. In case we need more time to master your paper, we may contact you regarding the deadline extension. In case you cannot provide us with more time, a 100% refund is guaranteed.
Original & Confidential
We use several writing tools checks to ensure that all documents you receive are free from plagiarism. Our editors carefully review all quotations in the text. We also promise maximum confidentiality in all of our services.
24/7 Customer Support
Our support agents are available 24 hours a day 7 days a week and committed to providing you with the best customer experience. Get in touch whenever you need any assistance.
Try it now!
How it works?
Follow these simple steps to get your paper done
Place your order
Fill in the order form and provide all details of your assignment.
Proceed with the payment
Choose the payment system that suits you most.
Receive the final file
Once your paper is ready, we will email it to you.
Our Services
No need to work on your paper at night. Sleep tight, we will cover your back. We offer all kinds of writing services.
Essays
No matter what kind of academic paper you need and how urgent you need it, you are welcome to choose your academic level and the type of your paper at an affordable price. We take care of all your paper needs and give a 24/7 customer care support system.
Admissions
Admission Essays & Business Writing Help
An admission essay is an essay or other written statement by a candidate, often a potential student enrolling in a college, university, or graduate school. You can be rest assurred that through our service we will write the best admission essay for you.
Reviews
Editing Support
Our academic writers and editors make the necessary changes to your paper so that it is polished. We also format your document by correctly quoting the sources and creating reference lists in the formats APA, Harvard, MLA, Chicago / Turabian.
Reviews
Revision Support
If you think your paper could be improved, you can request a review. In this case, your paper will be checked by the writer or assigned to an editor. You can use this option as many times as you see fit. This is free because we want you to be completely satisfied with the service offered.