Mathematics – Statistics STA200 Homework 4:

•   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?

STA

0

Homework 4: Based on Chapter 4.

· To calculate the correlation factor (r), go to Excel, Formulas, Statistics, and select the CORREL function.

· To calculate the Regression Equation and Coefficient of Determination:

a. Select the x,y data

b. Insert a scatter 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 Equation, and r square.

1) Exercise 2

3

, page 1

5

9.
Roadway congestion is a costly item, in both time wasted, and fuel wasted. Let

X

represent the average annual hours per person spent in traffic delays and let

Y

represent the average annual gallons of fuel wasted per person in traffic delays.
a) Draw a scatter diagram for the data.
b) Compute r (Coefficient of Correlation).
c) Is there a correlation?

20

28

5

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 information (units in hundreds of jobs).

3

28

5

50

9

3

a) Calculate the media of jobs.
b) Calculate the media of entry-level jobs.
c) Compute r (Coefficient of Correlation).
d) Draw a scatter diagram for the data, showing the regression line.
e) Calculate the Coefficient of Determination.
f) Calculate the Regression Equation.
g) Question: If a neighborhood with 40 jobs, how many are predicted to be entry-level jobs?