Reference no: EM131093826
Refer to Muscle mass Problem 1.27.
a. Fit a two-region regression tree. What is the first split point based on age? What is SSE for this two-region tree?
b. Find the second split point given the two region tree in part (a). What is SSE for the resulting three-region tree?
c. Find the third split point given the three-region tree in part (b). What is SSE for the resulting four-region tree?
d. Prepare a scatter plot of the data with the four-region tree in part (c) superimposed. How well does the tree fit the data? What does the tree suggest about the change in muscle mass with age?
e. Prepare a residual plot of 
versus Yi for the four-region tree in part (d). State your findings.
Problem 1.27
Muscle mass. A person's muscle mass is expected to decrease with age. To explore this relationship in women, a nutritionist randomly selected 15 women from each lO-year age group, beginning with age 40 and ending with age 79. The results follow; X is age, and Y is a measure of muscle mass. Assume that first-order regression model (1.1) is appropriate.
a. Obtain the estimated regression function. Plot the estimated regression function and the data. Does a linear regression function appear to give a good fit here? Does your plot support the anticipation that muscle mass decreases with age?
b. Obtain the following: (1) a point estimate of the difference in the mean muscle mass for women differing in age by one year, (2) a point estimate of the mean muscle mass for women aged X = 60 years, (3) the value of the residual for the eighth case, (4) a point estimate of σ2.
|
Measure of security to the database
: The navigation forms can provide some measure of security to the database as they may prevent users unfamiliar with Access from entering database objects directly; they make using Access more intuitive to use, and can prevent new users from inadve..
|
|
Effective in preventing gun related accidents
: Should gun manufacturers have a duty to warn gun users of the dangers of using a gun? Would such a warning be effective in preventing gun related accidents?
|
|
Explain an example of an organizational politics
: Please produce and explain an example of an organizational politics event in your life. It could be an example of friend behaving politically or some application of political behavior in a group that you are a part of.
|
|
Outsourcing manufactoring and product development
: What distinctives should a Christian business epouse when considering outsourcing manufactoring and product development? How could a christian business use outsourcing to help support poor nations and economies, global missions, and evangelism?
|
|
Fit a two-region regression tree
: a. Fit a two-region regression tree. What is the first split point based on age? What is SSE for this two-region tree? b. Find the second split point given the two region tree in part (a). What is SSE for the resulting three-region tree?
|
|
What is the quantity consumed
: Economics 236 - Health Economics & Policy Problem Set 1. Suppose that the demand for dental visits is given by: Q = 1000 - 15 P, where Q is the quantity of visits and P is the price. What is the quantity consumed at P = 50
|
|
Probability that the third heart is drawn
: From an ordinary deck of 52 cards, cards are drawn one by one, at random and without replacement. What is the probability that the third heart is drawn on the eleventh draw?
|
|
Second-order regression model
: a. Fit regression model (8.2). Plot the fitted regression function and the data. Does the quadratic regression function appear to be a good fit here?
|
|
The basis of the weighted least squares fit
: a. On the basis of the weighted least squares fit in Problem II. 7e, construct an approximate 90 percent confidence interval for ß1 by means of (6.50), using the estimated standard deviation s{bn-1}.
|