BST 322,
Week 4 Assignment
Week 4 Assignment
1.
For each correlation coefficient below, calculate what proportion of variance is shared by the two
correlated variables:
a.
r

b.
r

c.
r

d.
r

2.
For each coefficient of determination below, calculate the value of the correlation coefficient:
a.
r
2

b.
r
2

c.
r
2

d.
r
2

3.
Suppose a researcher regressed surgical patients’ length of stay (dependent variable) in the hospital on a
scale of functional ability measured 24 hours after surgery.
Given the following, solve for the value of
the intercept constant and write out the full regression equation:
Mean length of stay = 6.5days; mean score on scale = 33; slope = -0.10