Explore BrainMass

Regression Analysis

Hi Basil Sunny,

I used your service the past few weeks and had some great success with your answer. I am not sure if you remember, but here is a new list of questions let me know if you can tackle these....i did not want to post the questions to all other TAs so i chose you specifically (i believe you can solve them, if not let me know i will make the posting public to everyone else)

Question 1:
Solve Exercise 11.6 (In a certain type of metal test) on page 399 of Walpole textbook. Show all your work.

Here is the description of exercise 11.6:

In a certain type of metal test specimen, the normal stress on a specimen is known to be functionally related to the shear resistance. The following is a set of coded experimental data on two variables:

Normal Stress, x Shear Resistance, y
26.8 26.5
25.4 27.3
28.9 24.2
23.6 27.1
27.7 23.6
23.9 25.9
24.7 26.3
28.1 22.5
26.9 21.7
27.4 21.4
22.6 25.8
25.6 24.9

(a) Estimate the regression line MU Y|x = B0 + B1x
(b) Estimate the shear resistance for a normal stress of 24.5

Question 2:
With reference to Question 1 above test the hypothesis:
H0: B0 = 20
Ha: B0 > 20
Use a significance level of 2.5%. Do not use a STAT package or any software for this question. Show all your calculation steps. Interpret the result.

Question 3:
a) With reference to Question 1 above, construct a 99% confidence interval for B0.
b) With reference to Question 1 above, construct a 99% confidence interval for B1.
c) Find R2. Interpret the result.
d) Based on the information in part (c) above, does the linear model seem appropriate? what additional information would you need to better answer this question?

Note: See attachment containing the word document with the same information as above but in better format (I have attached both 2010 word document and 2003-2007 word document formats just in case can't open either)


Solution Summary

The solution provides step by step method for the calculation of regression analysis. Formula for the calculation and Interpretations of the results are also included.