Regression question

Figure 2: http://d.yimg.com/hd/answers/i/86d4de92a2314c0c9a254e39846d1863_A.png?a=answers&mr=0&x=1386231910&s=3309fe521a70e6891ff628849d0f49de
Regression analysis of the number refused/positive results v. the number of tests taken


Question 32

Figure 2 plots the number of refused/positive results between 2000 and 2006 against the total number of tests and also includes the estimated regression line ‘y on x’.

The gradient of the line of best fit is:

A. 141.3600031: this suggests that for each additional ‘thousand’ test, the number of refused/positive results increases by about 141 360

B. -0.064446131: this suggests that for each additional ‘thousand’ test, the number of refused/positive results decreases by about 64

C. 0.894478506 : this suggests that for each additional ‘thousand’ test, the number of refused/positive results increases by about 894

D. 0.800091797: this suggests that for each additional ‘thousand’ test, the number of refused/positive results increases by about 800

E. None of the above


Question 33

Using the statistics in the summary output adjacent to figure 2, estimate the number of refused/positive results if 640 (thousand) tests were conducted. State your answer to the nearest thousand.

A. 98 670
B. 100 114
C. 90 473
D. 90 470 337
E. None of the above