Biostats SSC 328M Homework 11
Write
your answers onto one or more separate sheets of paper. Clearly mark each sheet
with your name, your EID, and your lab section.
Scientists studied the relationship between the
length of the body of a bullfrog and how far it can jump. The results are given in the following table:
Bullfrog

Length (mm)

Maximum Jump (cm)

1

155

71.0

2

127

70.0

3

136

100.0

4

135

120.0

5

158

103.3

6

145

116.0

7

136

109.2

8

172

105.0

9

158

112.5

10

162

114.0

11

162

122.9

Mean

149.64

103.99

Standard Deviation

14.47

17.94

Correlation

0.28


1. Sketch
a scatter plot that predicts a bullfrogs maximum jump based on its body length.
(1 pt)
2. Calculate
the linear regression equation that predicts a bullfrogs maximum jump based on its
body length. Show all of your work and
any formulas you use. (2 pts)
3. Within
the context of the problem, what does the slope of the regression equation
mean? (1pt)
4. If
you measured a bull frog with body length 130 mm, and measured its jump
distance at 100 cm, what is the residual? (1
pt)
5. What
proportion of the variation in maximum jump distances can be explained by the
linear relationship between jump distance and frog length? (1 pt)
6. How
would you confirm that a linear regression analysis is appropriate for this
data? (1pt)
7.
Perform a test of correlation to
determine if a frogs body length is related to its jump distance. Include all steps in the testing procedure at
a 5% level of significance. (3 pts)