Question

A forensic psychologist tests the extent to which the age of a criminal (X) predicts the age of the victim (Y) for nonviolent crimes. The psychologist uses the case files to record the age of five criminals and the age of the victim in those cases. The hypothetical data are listed in the following table.

Age of Criminal	Age of Victim
X	Y
33	25
25	21
29	25
17	22
13	16

(a) Compute the method of least squares to find the equation of the regression line. (Round your answers to three decimal places.)
=  X +

(b) Use the regression equation to determine the predicted age of a victim of a nonviolent crime when the criminal is 20 years old. (Round your answer to three decimal places.)
years old

Answer 1

The statistical software output for this problem is :

Simple linear regression results:
Dependent Variable: y
Independent Variable: x
y = 12.752907 + 0.38662791 x
Sample size: 5
R (correlation coefficient) = 0.86641734
R-sq = 0.750679
Estimate of error standard deviation: 2.1340721

Predicted values:

X value	Pred. Y	s.e.(Pred. y)	95% C.I. for mean	95% P.I. for new
20	20.485465	1.0498373	(17.144414, 23.826516)	(12.916579, 28.054351)

(a)

y = 0.387 x + 12.753

(b) predicted age = 20.485