7.1

31.

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

Interpretation 1.15.87% of randomly selected cell phone monthly charges in the USA are less than or equal to $44

Interpretation 2. 15.87% of monthly cell phone charges in the united states are less than or equal to $44

32.

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

Interpretation 1. The probability of selecting a fridge that is more than 17 years old is .1151

Interpretation 2. The percentage of fridges that are more than 17 years old is 11.51%

33.

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

Interpretation 1. The probablity of a randomly selected birth weight being more than 4410 grams is .0228

Interpretation 2. 2.28% of full term babies have birth weights more than 4410 grams

34.

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

Interpretation 1. The probability of randomly selecting a 10 year old male who is less than 46.5 inches tall is .0496

Interpretation 2. The percentage of 10 year old males who are less than 46.5 inches tall is 4.96%

35.

Interpretation 1. The probablity of randomly selecting a human pregnancy that lasts more than 280 days is .1908

Interpretation 2. 19.08% of human pregnancies last more than 280 days

Interpretation 1. The probability of randomly selecting a human pregnancy that will last between 230 and 260 days is .3416

Interpretation 2. The percentage of pregnancies that last between 230 days and 260 days is 34.16%

36.

Interpretation 1. The probability of randomly selecting a fill up that provides more than 26 miles to the gallon is .3309

Interpretation 2. The percentage of fill ups that provide more than 26 miles to the gallon is 33.09%

Interpretation 1. The probability that a fill up gives between 18 and 21 miles to the gallon is .1107

Interpretation 2. The percentage of fill ups that provide between 18 and 21 miles to the gallon is 11.07%

7.2

5.

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

7.

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

9.

(a).9586 (b).2088 (c).8479

11.

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

13. -1.28

15. 0.67

17. -2.575, 2.575

33. 40.62

35. 56.16

37.

  1. .1587
  2. .1587
  3. .4772
  4. yes, because the probability of this occurring is low- its around .0013

39.

  1. .08658
  2. .0132
  3. .7019
  4. .1230
  5. 96th percentile
  6. 4th percentile

41.

  1. .4013
  2. .1587
  3. .7590
  4. .1894
  5. .0951
  6. unusual. the probability is .0043, which translates to 4 out of 1000 births

43.

  1. .0764
  2. .0324
  3. 162
  4. 11,804

45.

  1. .3228
  2. .4285
  3. yes, and it means the spreads are accurate because the favored team has an equal chance of winning or losing

47.

  1. 20 days
  2. 19 to 23 days

56. the SAT