Exam 7: Introduction to Linear Regression

Consider the following to answer the question(s) below: A small independent organic food store offers a variety of specialty coffees. To determine whether price has an impact on sales, the managers kept track of how many kilograms of each variety of coffee were sold last month. The data, scatterplot, and summary statistics are shown below. Note: In answers to problems 2, 4, and 5 we will be using regression equation coefficients received by computer software. If we apply textbook formulae, the value of intercept will be a little bit different. -Find the value of R2. Interpret its meaning in this context.

Consider the following to answer the question(s) below: To determine whether the cash bonuses paid by Johnson Financial Group are related to annual pay, data were gathered for 10 account executives who received such bonuses in 2007. The data, scatterplot and summary statistics are shown below. Note: In answers to problems 2, 4, and 5 we will be using regression equation coefficients received by computer software. If we apply textbook formulae, the value of intercept will be a little bit different. -Using the regression equation, a. Estimate the cash bonus for an executive at Johnson Financial Group earning $82,613 a year. b. What is the residual for this estimate? What does it mean?

Consider the following to answer the question(s) below: A small independent organic food store offers a variety of specialty coffees. To determine whether price has an impact on sales, the managers kept track of how many kilograms of each variety of coffee were sold last month. The data, scatterplot and summary statistics are shown below. -The slope of the estimated regression line that relates the response variable (Kilograms Sold) to the predictor variable (Price per Kilogram) is

Consider the following to answer the question(s) below: To determine whether the cash bonuses paid by Johnson Financial Group are related to annual pay, data were gathered for 10 account executives who received such bonuses in 2007. The data, scatterplot and summary statistics are shown below. Note: In answers to problems 2, 4, and 5 we will be using regression equation coefficients received by computer software. If we apply textbook formulae, the value of intercept will be a little bit different. -Using the regression equation, a. Estimate the cash bonus for an executive at Johnson Financial earning $200,000 a year. b. How confident should you be in this estimate? Explain.

Consider the following to answer the question(s) below: To determine whether the cash bonuses paid by Johnson Financial Group are related to annual pay, data were gathered for 10 account executives who received such bonuses in 2007. The data, scatterplot and summary statistics are shown below. Note: In answers to problems 2, 4, and 5 we will be using regression equation coefficients received by computer software. If we apply textbook formulae, the value of intercept will be a little bit different. -Below is a plot showing residuals versus fitted values for the estimated regression equation relating cash bonus to annual pay for the account executives at Johnson Financial Group. Are all the conditions for linear regression met? Explain.

Consider the following to answer the question(s) below: To determine whether the tip left at the end of a meal is related to the size of the total bill at their restaurant, Chez Michelle, data were gathered for 10 customers. The data and summary statistics are shown below. -The regression equation would predict what size of tip if the total bill was $120?

Consider the following to answer the question(s) below: A small independent organic food store offers a variety of specialty coffees. To determine whether price has an impact on sales, the managers kept track of how many kilograms of each variety of coffee were sold last month. The data, scatterplot, and summary statistics are shown below. Note: In answers to problems 2, 4, and 5 we will be using regression equation coefficients received by computer software. If we apply textbook formulae, the value of intercept will be a little bit different. -Below is a plot showing residuals versus fitted values for the estimated regression equation relating monthly sales of coffee to price per kilogram. Are all the conditions for linear regression met? Explain.

Consider the following to answer the question(s) below: A small independent organic food store offers a variety of specialty coffees. To determine whether price has an impact on sales, the managers kept track of how many kilograms of each variety of coffee were sold last month. The data, scatterplot, and summary statistics are shown below. Note: In answers to problems 2, 4, and 5 we will be using regression equation coefficients received by computer software. If we apply textbook formulae, the value of intercept will be a little bit different. -Estimate the linear regression model that relates the response variable (Kilograms Sold) to the predictor variable (Price per Kilogram). a. Find the slope of the regression line. b. Find the intercept of the regression line. c. Write the equation of the linear model.

Consider the following to answer the question(s) below: To determine whether the cash bonuses paid by Johnson Financial Group are related to annual pay, data were gathered for 10 account executives who received such bonuses in 2007. The data, scatterplot and summary statistics are shown below. -Based on the estimated regression equation, the cash bonus for an executive at Johnson Financial Group earning $82,613 a year would be

Consider the following to answer the question(s) below: A small independent organic food store offers a variety of specialty coffees. To determine whether price has an impact on sales, the managers kept track of how many kilograms of each variety of coffee were sold last month. The data, scatterplot, and summary statistics are shown below. Note: In answers to problems 2, 4, and 5 we will be using regression equation coefficients received by computer software. If we apply textbook formulae, the value of intercept will be a little bit different. -Using the estimated regression equation, a. Estimate the monthly sales for a variety of coffee that costs $20.00 per kilogram. b. How confident should you be in this estimate? Explain.

Consider the following to answer the question(s) below: To determine whether the cash bonuses paid by Johnson Financial Group are related to annual pay, data were gathered for 10 account executives who received such bonuses in 2007. The data, scatterplot and summary statistics are shown below. -The slope of the estimated regression line that relates the response variable (Cash Bonus) to the predictor variable (Annual Pay) is

Consider the following to answer the question(s) below: To determine whether the cash bonuses paid by Johnson Financial Group are related to annual pay, data were gathered for 10 account executives who received such bonuses in 2007. The data, scatterplot and summary statistics are shown below. Note: In answers to problems 2, 4, and 5 we will be using regression equation coefficients received by computer software. If we apply textbook formulae, the value of intercept will be a little bit different. -Estimate the linear regression model that relates the response variable (Cash Bonus) to the predictor variable (Annual Pay). a. Find the slope of the regression line. b. Find the intercept of the regression line. c. Write the equation of the linear model.