7.1

31. {r} shadenorm(mu = 62, sig = 18, below = 44, col = "blue", dens = 200)

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

Interpretation 1. 15.87% of the population pays less than $44

Interpretation 2. There is a 15.87% chance that any individual pays less than $44

32. {r} shadenorm(mu = 14, sig = 2.5, above = 17, col = "blue", dens = 200)

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

Interpretation 1. 11.51% of refrigerators last longer than 17 years

Interpretation 2. There is a 11.51% chance that any refrigerator lasts longer than 17 years

33. {r} shadenorm(mu = 3400, sig = 505, above = 4410, col = "blue", dens=200)

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

Interpretation 1. 2.28% of the population are heavier than 4410 grams

Interpretation 2.There is a 2.28% chance of any individual being heavier than 4410 grams

34.

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

Interpretation 1. 4.96% of the population are shorter than 46.5 inches tall

Interpretation 2. There is a 4.96% that any individual is shorter than 46.5 inches tall

35.

Interpretation 1. 19.08% of pregnancies last longer 280 days

Interpretation 2. There is a 19.08% chance that any pregnancy will last longer than 280 days

Interpretation 1. 34.16% of pregnancies last between 230 and 260 days

Interpretation 2. There is a 34.16% chance that any pregnancy will last between 230 and 260 days

36.

Interpretation 1. 33.09% of the times her car got more than 26 mpg

Interpretation 2. There is a 33.09% chance a fillup will give her more than 26 mpg

Interpretation 1. 11.07% of the times her car got between 18 and 21 mpg

Interpretation 2. There is a 11.07% chance a fillup will give her between 18 and 21 mpg

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. -1.28

15. .67

17. -2.575 and 2.575

33. 40.62

35. 56.16

37.

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

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

  1. .1587
  2. .1587
  3. .4772
  4. The probability of this occurring is very small (~ 1 in 1000)

39.

  1. .8658
  2. .0132
  3. .7019
  4. .1230
  5. 96th
  6. 4th

41.

  1. .4013
  2. .1587
  3. .7590
  4. .1894
  5. .0951
  6. yes (~ 4 in 1000)

43.

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

45.

  1. There is equal probability that a team will or will not clear the spread. Spreads are accurate (due to the 0 mean)
  2. .3228
  3. .4286

47.

  1. 20 days
  2. between 19 and 23 days

56. SAT score is better because it has a higher z-score