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?