Homework for Stats 343

Due: March 19, 2004

You are interested in modeling the relationship between (a) the degree to which teachers of a country approve of corporal punishment and (b) the homicide rate of that country. Let’s assume that a linear model, Y = a + bX, is an appropriate one for modeling this relationship.

1. Use the following data to obtain least-squares estimates of the parameters a and b.

Countries	X (approval of corporal punishment)	Y (homicide rate)
A	-1.00	1.5
B	-0.75	1.5
C	-0.50	1.6
D	-0.40	1.8
E	-0.75	2.3
F	-0.50	2.3
G	0.50	2.3
H	0.70	2.3
I	1.30	2.8
J	1.50	2.3

2. Create a scatterplot of the data.

3. What is the correlation between these two variables?

4. Given the model, and the least-squares estimates of the model’s parameters, what does homicide rate does the model imply for a nation that has a corporal punishment approval score of 3.00?

5. What is the R-squared for the model?