"An automobile dealer wants to see if there is a relationship between monthly sales and the interest rate. A random sample of 4 months was taken. The results of the sample are presented below. The estimated least squares regression equation is
In excel and without using excel's regression feature construct a 99% confidence interval for the average monthly sales for all months with a 10% interest rate. report the upper bound of the CI.
y = 75.061 - 6.254X
Monthly Sales Interest Rate (In Percent)
y x
22 9.2
20 7.6
10 10.4
45 5.3