Suppose a professor records the number of days absent and th

Suppose a professor records the number of days absent and the final exam score for the students in his class. Use this data in the table below to answer questions a through d. Click the icon to view a table of critical values for the correlation coefficient. (a) Find the least-squares regression line, treating number of absences as the explanatory variable and final exam score as the response variable. y = x + (Round to two decimal places as needed.) (b) Interpret the slope and intercept, if appropriate. Choose the best interpretation for the slope. A. The slope indicates the ratio between the average final exam score and the average number of absences. B. The slope indicates the average number of absences. C. The slope indicates the average change in final exam score for an additional absence. D. The slope indicates the average final exam score. E. It is not appropriate to interpret the slope because it is not equal to zero.

Solution

(a)y=89.10-3.93*x

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(b)C

A

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(c) The predicted =89.10-3.93*1=85.17

The residual= 86.5-85.17=1.33

D

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(d)A

Regression output				confidence interval
variables	coefficients	std. error	t (df=3)	p-value	95% lower	95% upper
Intercept	89.1000	2.1318	41.796	3.01E-05	82.3156	95.8844
x	-3.9300	0.8703	-4.516	.0203	-6.6997	-1.1603