## 22 Sep 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 c

- 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?

**STA200**

**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 23, page 159. 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?

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 information (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 (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?