The management of a supermarket wants to find if there is a relationship between the number of
Question:
a. With the number of promotions as an independent variable and the number of units sold as a dependent variable, what do you expect the sign of B in the regression line y = A + Bx + E will be?
b. Find the least squares regression line Å· = a + bx. Is the sign of b the same as you hypothesized for B in part a?
c. Give a brief interpretation of the values of a and b calculated in part b.
d. Compute r and r2 and explain what they mean.
e. Predict the number of units of this product sold on a day with 35 promotions.
f. Compute the standard deviation of errors.
g. Construct a 98% confidence interval for B.
h. Testing at a 1% significance level, can you conclude that B is positive?
i. Using α = .02, can you conclude that the correlation coefficient is different from zero?
Step by Step Answer: