7.2

5.

  1. 0.0071.
  2. 0.3336.
  3. 0.9115.
  4. 0.9998.

7.

  1. 0.9987.
  2. 0.9441.
  3. 0.0375.
  4. 0.0009.

9.

  1. =0.9586.
  2. =0.2088.
  3. =0.8479.

11.

  1. Total area = 0.0456.
  2. =0.0646.
  3. =0.5203.

13. z=-1.28.

15. z=0.67.

17. z=-2.575.

33. x= 40.62 (at the 9th percentile).

35. x= 56.16 (at the 81st percentile).

37.

  1. P (x <20) = 0.1587, If 100 were selected at random, 16 would incubate in less that 20 days.
  2. p (x>22) = 0.1587, If 100 were selected at random, we would expect 16 5o incubate in less that 22 days.
  3. If 100 were selected at random, we would expect 48 to incubate between 19 and 21 days.

39.

  1. =0.8657.
  2. =0.0132.
  3. =0.7019, or 70.19%.
  4. =0.1230 or 12.30%.
  5. =0.9649.
  6. =0.0359.

41.

  1. =0.4013 of pregnancies last more than 270 days.
  2. =0.1587 of pregnancies last fewere than 250 days.
  3. =0.7590 ofpregnancies last from 240-280 days.
  4. =0.1894.
  5. =0.0951.
  6. Yes, 0.0043 of births are very preterm.

43.

  1. =0.0764.
  2. =0.0324.
  3. =plan manager expects to discard 162 of 5000.
  4. =manager to manufacture 11,804.

45.

  1. Yes, mean of 0 implies that the spreads are accurate.
  2. =0.3228.
  3. =0.4286.

47.

  1. 17th percentile for incubation time is 20 days.
  2. 19-23 days make up the middle 95% of incubation time of the eggs.

56. ACT = 0.96; SAT = 1.02// Score on the sAT is in the 84th percentile, you did better on the SAT.