Answers:
- 6. A) 120 plus or minus 1
- 7. A) (0, 22.7)
- 8. B) When there are 0 people, the max noise is 22.7 dB
- 9. D) 89
- 10. B) The player had 318 at bats and 80 hits.
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Explanations:
- 6. Plug in x = 65 and evaluate. You should get y = 120.2 which is fairly close to 120, give or take a decibel or so.
- 7. The y intercept is the value of b in y = mx+b. In this case, b = 22.7 and the location of the y intercept is (0, b) = (0, 22.7)
- 8. Plug in x = 0 and you should get y = 22.7, which is the y intercept mentioned earlier. It means that if x = 0 people show up, ie the stadium is empty, then the noise level is 22.7 dB. This is probably unrealistic as there's no people around to make noises, unless there are machinery or similar making sounds.
- 9. Form the proportion 147/526 = x/317. Solve for x to get roughly x = 88.591, which rounds to 89. If we have 89 in this cell, then the row relative frequencies will fairly be the same (ie each row is pretty much identical after we compute the row relative frequencies) and that leads to a likely case we don't have association.
- 10. The point (x,y) = (318, 80) means x = 318 and y = 80 pair up together. The variable x is the number of at bats, and y is the number of hits.
