Question

2. The owner of Red’s Towing and Garage Service is interested in finding the relationship between the lowest temperature on a winter day and the number of emergency service calls his shop receives. The following table gives the lowest temperature on seven winter days and the number of service calls received on those days. (Use the printout on the following page)

Temperature: 15, 0, 24, -10, 30, 9, 36

# of Calls: 12, 22, 16, 31, 7, 24, 6

a. Compute(Fill in the equation) the Regression line using temperature as the Independent variable and number of calls as the dependent variable. (You are identifying from the summary output the values for a and b in the regression formula y=a+bx)

b. Is there a positive or negative relationship?

c. Evaluate the strength of the relationship

d. How good is the model according to the Coefficient of Determination? (Elaborate)

e. Predict the number of calls when the temperature is 20 degrees.f. Predict the number of calls when the temperature is -5 degrees.

Answer 1

X	y	(x-xbar)^2	(y-ybar)^2	(x-xbar)(y-ybar)
15 0 24 -10 30 9 36	12 22 16 31 7 24 6	0.020 220.735 83.592 617.878 229.306 34.306 447.020 Sum: 1632.857	23.592 26.449 0.735 200.020 97.163 51.020 117.878 Sum: 516.857	-0.694 -76.408 -7.837 -351.551 -149.265 -41.837 -229.551 Sum: -857.143