The following table gives information on ages and cholesterol levels for a random sample of 10
men.
Age58694339635247317436
Cholesterol level189235193177154191213165198181
a. Taking age as an independent variable and cholesterol level as a dependent variable,
compute SSxx, SSyy, and SSxy.
b. Find the regression of cholesterol level on age.
c. Briefly explain the meaning of the values of aand bcalculated in part b.
d. Calculate rand r
2
and explain what they mean.
e. Plot the scatter diagram and the regression line.
f. Predict the cholesterol level of a 60yearold man.
g. Compute the standard deviation of errors.
h. Construct a 95% confidence interval for B.
i. Test at the 5% significance level if Bis positive.
j. Using α = .025, can you conclude that the linear correlation coefficient is positive?
25 answers