1. A study in transportation safety collected data on 42 North American cities. From each city, two of the variables recorded were explanatory variable x=percentage of licensed drivers who are under 21 years of age, and the response variable y=the number of fatal accidents per year per 1000 licenses. Of interest is the relationship between these two variables.

The data were analyzed. Examine carefully the output below:

Regression Analysis - Linear model: Y = a + b*X

Parameter	Std. Estimate	Error	T Statistic	p-value
Intercept	-1.59741	0.371671	-4.29792	0.0001
Slope	0.287053	0.0293898	9.76711	0.0000

Correlation Coefficient = 0.839387

R-squared = 70.4571 percent

Standard error of estimate = 0.58935

a) What is the correlation coefficient in this question, and what does it indicate about the relationship between the number of fatal accidents and the percentage of licensed drivers?

b) Is there a significant linear relationship between the number of fatal accidents and the percentage of licensed drivers? Support your answer using a decision point and show all necessary steps?

c) Write down the equation of the estimated regression line in the context of this question.

d) Provide an interpretation of the slope of the estimated regression line in (c), paying special attention to the units of measurement for the data.

e) Provide an estimate of the number of fatal accidents when the percentage of licensed drivers who are under 21 years of age is 35.

2. In the following data set variable "Years" represent the years of experience and variable sales represents the

number of sales.

Years	Sales
1	80
3	97
4	92
4	102
6	103
8	111
10	119
10	123
11	117
13	136
7	108

a. Use excel and make the appropriate graph. (use the appropriate title,....)

b) Use excel and fit a least square regression line.

c) Provide an interpretation of the slope estimate.

Provide an interpretation of the intercept estimate.

Assignment 3 Due Oct 26