Exam 7: Introduction to Linear Regression

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. -Comment on whether each of the following conditions for correlation / linear regression is met. a. Quantitative Variables Condition b. Linearity Condition c. Outlier Condition

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 slope of the estimated regression line that relates the response variable (Tip) to the predictor variable (Total Bill) is

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. -Comment on whether each of the following conditions for correlation / linear regression is met. a. Quantitative Variables Condition b. Linearity Condition c. Outlier Condition

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 (kilograms sold) for a variety of coffee that costs $12.00 per kilogram. b. What is the residual for this estimate? What does it mean?

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 residual for the estimated tip for a total bill of $120 would be

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. -What percent of the variation of the cash bonus can be explained by variation of the annual pay?

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. -Which of the following is a correct interpretation for the regression slope coefficient b1?

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. -Which of the following statements is true?

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. -Analyze the scatterplot below. What solution strategy would be most appropriate?

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. -Below is a plot showing residuals versus fitted values for the estimated regression equation relating monthly sales (kilograms sold) of coffee to price per kilogram. Based on this plot we can say

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 intercept of the estimated regression line that relates the response variable (Tip) to the predictor variable (Total Bill) is

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 intercept 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: 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. -A pair of variables, x and y, have a correlation coefficient of -0.8851. Which of the following statements is true?

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. -A regression of two variables, x and y, results in the value of R2 equal to 0.7834. Which of the following statements is true?

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, = -3.61+0.106x, expresses statistical dependence of vacation expenses (y) on personal income (x) in a sample of 45 clients of a large travel agency (both numbers in $thousands). A client with $80,000 income is expected to spend

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. -What percent of the variation of the number of kilograms of coffee sold per month can be explained by variation of price per kilogram?

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 intercept 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. -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. -Based on the estimated regression equation, the residual for the estimated cash bonus of an executive at Johnson Financial Group earning $82,613 a year would be

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 percentage of the variation of the tip that can be explained by the variation of the total bill is