OPMT 1197 Quiz 22 Mark: /12 Last Name: First Name: Student ID#: B1 = Sample Slope + tn-2 X Standard Error (Standard Error from the Excel output) t-score = T.INV.2T (1 - confidence level, df = n - 2) The manager of a chain of furniture stores believes that experience is the most important factor in determining the level of success of a salesperson. To examine this belief he records last month's sales and the years of experience for 30 randomly selected salespeople. Below is the linear regression output to predict Monthly Sales (in $1,000's) based on Years of Experience: SUMMARY OUTPUT Regression Statistics Multiple R 0.6921 R Square 0.479 Observations Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Intercept 18.5 4.608 4.017 0.0004 27.9 Years of Experience 1.82 0.3587 5.074 0.0000 1.09 2.55 (a) Construct a 90% confidence interval for the population slope. (3 marks) ANSWER: (b) One of your salespeople with 12 years of experience had $25,000 in sales last month. Is this low for a salesperson with 12 years of experience? Explain using the regression line. (2)(d) Is there enough evidence to conclude there is a linear relationship between monthly sales and years of experience? Test at the 5% significance level (95% confidence level). (5 marks) I I Decision/Why Conclusion: Circle the Correct One (1 mark) A. Yes, there is enough evidence to conclude there is a linear relationship B. No, there is not enough evidence to conclude there is a linear relationshipSUMMARY OUTPUT Regression Statistics Multiple R 0.6921 R Square 0.479 Observations Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Intercept 18.5 4.608 4.017 0.0004 9.1 27.9 Years of Experience 1.82 0.3587 5.074 0.0000 1.09 2.55 OPMT 1197 Quiz 22 Mark: /12 (c) Interpret r2 (the coefficient of determination) using the words of the problem. (2 marks) (d) Is there enough evidence to conclude there is a linear relationship between monthly sales and years of experience? Test at the 5% significance level (95% confidence level). (5 marks) I Decision/Why