7.1

31.

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

Interpretation 1. the proportion of charges for cell phone plans in the US that are less than 44 dollars is .1587

Interpretation 2. the probability that a randomly selected cellphone plan is below 44 dollars is .1587

32.

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

Interpretation 1. the proportion of refrigerators that live longer than 17 years is .1151

Interpretation 2. the probability that a randomly selected refrigerator lives longer than 17 years is .1151

33.

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

Interpretation 1. the probability that a randomly selected baby weighs more than 4410 grams is .0228

Interpretation 2. the proportion of babies that weigh more than 4410 grams is .0228

34.

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

Interpretation 1. the proportion of 10 year old males who are shorter than 46.5 inches tall is .04

Interpretation 2. the probability that a randomly selected boy is shorter than 46.5 inches is .04

35.

Interpretation 1. the proportion of pregnancies that are longer than 280 days is .1908

Interpretation 2. the probability that a randomly selected pregnancy is longer than 280 days is .1908

Interpretation 1.the proportion of pregnancies that are between 230 and 260 days is .3416

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

36.

Interpretation 1. The proportion of mpg in a Toyota Camry for each fill up that is above 26 mpg is .3309

Interpretation 2. The probability that a randomly selected fill up is above 26 mpg is .3309

Interpretation 1. The proportion of mpg in a Toyota Camry for each fill up that is between 18 and 21 mpg is .1107

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

7.2

5.

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

7.

  1. .9987
  2. .8621
  3. .0375
  4. .0009

9.

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

11.

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

13. -1.28

15. .67

17. 2.58 and -2.58

33. 40.62

35. 56.16

37.

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

  1. The probability that a randomly selected egg incubates in less than 20 days is .16
  2. The probability that a randomly selected egg incubates in longer than 22 days is .16
  3. The probability that a randomly selected egg incubates inbetween 19 and 21 days is .4772
  4. Yes because it falls below 3 standard deviations from the meanwhich would make it an outlier. The probability is .0013

39.

  1. .8658
  2. .0132
  3. .6985
  4. .123
  5. The 96th percentile
  6. The 4th percentile

41.

  1. .4013
  2. .1587
  3. .759
  4. .1894
  5. .0951
  6. yes, the probability is .0043 so only 4 out of 1000 births would be preterm

43.

  1. .0764 of rods have a length less than 24.9 cm
  2. .0324 of the rods will be discarded
  3. 162 of the rods would expect to be discarded
  4. 11804 rods should be manufactored so that you can get 10000 for the order