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The manager of a car dealership believes there is a relationship between the num

ID: 3150324 • Letter: T

Question

The manager of a car dealership believes there is a relationship between the number of salespeople on duty and the number of cars sold. For five weeks he recorded the number of people on duty and how many cars were sold: The manager then used simple linear regression to calculate the line y = 9.23 + 10.52x. where s_x^2 = 3.2, s_y^2 = 428.3, s_xy = 33.65, and SSE = 297.8. 8. What proportion of the variation in y is explained by the variation in x? (A) .1 (B) .2 (C) .3 (D) .4 (E) .5 (F) .6 (G) .7 (H) .8 (I) .9 (J) 1 9. The manager wants to test his hypothesis that there is a positive linear relationship between the number of salespeople on duty and the number of cars sold, using the slope the the linear regression line he found. What is the observed value of the test status that should be used? (A) 1.0 (B) 1.5 (C) 2.0 (D) 2.5 (E) 2.75 (F) 3.0 (G) 3.25 (H) 3.5 (I) 3.75 (J) 4.0

Explanation / Answer

R2   = 0.826

Therefore, option H) is correct.

Lets see excel output as shown below:

approximately option I is correct.

3.75

SUMMARY OUTPUT Regression Statistics Multiple R 0.908941729 R Square 0.826175067 Adjusted R Square 0.768233423 Standard Error 9.963213588 Observations 5 ANOVA df SS MS F Significance F Regression 1 1415.403 1415.403 14.25874 0.032530472 Residual 3 297.7969 99.26563 Total 4 1713.2 Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Lower 95.0% Upper 95.0% Intercept 9.234375 12.51613 0.737798 0.514108 -30.59754357 49.06629357 -30.5975436 49.06629357 X Variable 1 10.515625 2.784803 3.776075 0.03253 1.653139437 19.37811056 1.653139437 19.37811056