To calculate the correla on factor (r), go to Excel, Formulas, Sta s cs, and select the CORREL func on.
To calculate the Regression Equa on and Coe cient of Determina on: a. Select the x,y data
b. Insert a sca er chart from that data
c. Click the chart, go to Chart Design
d. Go to Quick Layout
e. Select Layout 9
f. Then you get the Regression Equa on, and r square.
1) Exercise 23, page 159.
Roadway conges on is a costly item, in both me wasted, and fuel wasted. Let X represent the average annual hours per person spent in tra c delays and let Y represent the average annual gallons of fuel wasted per person in tra c delays.
a) Draw a sca er diagram for the data.
b) Compute r (Coe cient of Correla on).
c) Is there a correla on?
X (hr)
Y (gal)
28
48
5
3
20
24
35
55
20
34
23
38
18
28
5
9
2) Exercise 7, page 172.
Let X represent the total number of jobs in each neighborhood, and let Y represent the number of entry-level jobs in the same neighborhood. A sample of six neighborhoods gave the following informa on (units in hundreds of jobs).
X
Y
16
2
33
3
50
6
28
5
50
9
25
3
a) Calculate the media of jobs.
b) Calculate the media of entry-level jobs.
c) Compute r (Coe cient of Correla on).
d) Draw a sca er diagram for the data, showing the regression line.
e) Calculate the Coe cient of Determina on.
f) Calculate the Regression Equa on.
g) Ques on: If a neighborhood with 40 jobs, how many are predicted to be entry-level jobs?