Stat 351 Homework #1 (Review, Section XXXXXXXXXX)
Due date: Wednesday, June 17, 2020 at 11.59 p.m. CDT.
Submit your homework via one of the following methods.
1. Type your answers in a word document and submit as a word document file or pdf file.
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3. Write down your answers in separate sheets of paper and submit snapshot of the answer.
Make sure to show your work for full credit.
1. The National Center for health statistics reports that the systolic blood pressure for
males 35 to 44 years of age has mean 128. The medical director of a large company
looks at the medical records of 72 executives in this age group and finds that the mean
systolic blood pressure in this sample is �̄� = XXXXXXXXXXand standard deviation is S=15.
a) State the null and alternative hypotheses you would use to test whether the company’s
executives have less mean systolic blood pressure than from general public.
) Compute the test statistic.
c) With α = 0.05, what is your conclusion? (Please use the critical value approach).
2. Use the following dataset and answer the following questions.
x XXXXXXXXXX
y XXXXXXXXXX
Please do problems (b), and (c) BY HAND. You may use your calculator.
a) The following scatter diagram has been taken from Minitab for the above data.
What does the above scatter diagram indicate about the relationship between the
two variables?
) Find the intercept of the estimated regression equation (b0).
c) Find the slope of the estimated regression equation (b1).
d) Develop the least squares estimated regression equation in the form of
�̂� = ?0 + ?1?
e) Use the estimated regression equation from part (d) to predict the value of ?
when ? = 12.
3. In a regression analysis, the estimated regression equation is given by �̂� = 12 −
6?. If SSE = 510 and SST = 1000, then
a) Compute the coefficient of determination r2.
) Interpret the r2.
c) Based on the value of r2, is it a good fit?
d) What is the value of the sample co
elation coefficient?