Question

Following are age and price data for 8 randomly selected ambulances between 1 and 6 years old.​ Here, x denotes​ age, in​ years, and y denotes​ price, in hundreds of dollars. Use the information to complete parts​ (a) through​ (f).

x 6 1 6    2 6    2    4 5

y 280 390 245 350 275 370 335 300

a. Find the regression equation for the data points.

y with caret = _____+ ________ x ​(Round to two decimal places as​ needed.)

b. Graph the regression equation and the data points.

c. Describe the apparent relationship between the 2 variables

d. Identify the predictor and response variables

e. Identify outliners and potential influential observations.

f. Predict the value of the respons variable for 3-year old ambulance

Answer 1

Solution: We can use excel regression data analysis tool to find the equation of the regression line. The excel output is given below:

a. Find the regression equation for the data points.

Answer:

b. Graph the regression equation and the data points.

Answer:

c. Describe the apparent relationship between the 2 variables

Answer: From the above scatterplot, we clearly see there exists a strong negative linear relationship between x and y variables.

d. Identify the predictor and response variables

Answer: Age is the predictor variable and Price is the response variable.

e. Identify outliers and potential influential observations.

Answer: From the above scatterplot, we clearly see there are no outliers but the point (6,245) is an influential point.

f. Predict the value of the response variable for a 3-year old ambulance

Answer: