7.1

31.

shadenorm(mu = 62, sig = 18, below = 44, col = "blue", dens = 200)

Interpretation 1. 15.87% of cell phone plans in the U.S are less than $44 per month.

Interpretation 2. The probability is .1587 that a randomly selected cell phone plan is less than $44 per month.

32.

shadenorm(mu = 14, sig = 2.5, above = 17, col = "blue", dens = 200)

Interpretation 1. 11.51 % of fridges last more than 17 years.

Interpretation 2. The probability is .1152 that a randomlyy selected fridge lasts more than 17 years.

33.

shadenorm(mu = 3400, sig = 505, above = 4410, col = "blue", dens=200)

Interpretation 1. 2.28% of all full term babies have a birth weight of at least 4410 grams.

Interpretation 2.The probability is .0228 that the baby weight of a randomly chosen baby is at least 4410 grams.

34.

shadenorm(mu = 55.9, sig = 5.7, below = 46.5, col = "blue", dens=200)

Interpretation 1. 4.96 % of 10 year old males are 46.5 inches or less.

Interpretation 2. .0496 is the probability that a randomly selected 10 year old males is 46.5 inches or less.

35.

Interpretation 1. 19.08 % of human pregancies last more than 280 days.

Interpretation 2. The probability is .1908 that a randomly selected human has a pregnancy longer than 280 days.

Interpretation 1.The proportion of human pregnancies that last between 230 and 260 days is 34.16%.

Interpretation 2. The probability is .3416 that a randomly selected pregnancy lasts between 230 and 260 days.

36.

Interpretation 1. 33.09% of the fill ups have an average mpg that is over 26.

Interpretation 2. The probability is .3309 that a random fill up has a mpg over 26.

Interpretation 1. 11.07% of fill ups had a mpg in between 18 and 21.

Interpretation 2. The probability that a randomly selected fill up had a mpg between 18 and 21 is .1107.

7.2

5.

  1. .0071
  2. .3336
  3. .9115
  4. .9998

7.

  1. .9987
  2. .9441
  3. .0375
  4. .0009

9.

  1. .9586
  2. .2088
  3. .8479

11.

  1. .0456
  2. .0646
  3. .5203

13. z = -1.28

15. z = 0.67

17. +/- 2.575

33. 40.62

35. 56.16

37.

shadenorm(mu = 21, sig = 1.0, below = -1000, col = "blue", dens=200)

  1. .1587
  2. .1587
  3. .4772
  4. .0013 It would be unusual, only about 1 in 1000 hatches in less than 18 days.

39.

  1. .8658
  2. .0132
  3. 70.19%
  4. 12.30%
  5. 96th percentile
  6. 4th percentile

41.

  1. 40.13 %
  2. 15.87%
  3. 75.90%
  4. .1894
  5. .0951
  6. Yes, very unusual, only about 4 in 1000 births are preterm.

43.

  1. 7.64%
  2. 3.24%
  3. 162
  4. 11,804 rods.