7.1

31.

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

Interpretation 1. 15.87% of cell phone plans are les than $44 per month.

Interpretation 2. the probability that a randomly selected cell phone plan in the US is 0.1587 is less than $44 per month.

32.

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

Interpretation 1. 11.51% of all refrigerators are kept for more than 17 yrs.

Interpretation 2. the probability if 0.1151 refrigerator selected at random is more than 17 years old.

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 probabilty is 0.0228 that the birth weight of a full-term baby selected at random is at least 4410 grams.

34.

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

Interpretation 1. 10 yr old males who are less than 46.5 inches tall have a proportion of 4.96%.

Interpretation 2. probability that a 10 yr old male selected at random is is less than 45.6 inches tall is 0.0496

35.

Interpretation 1: The proportion is 19.08%

Interpretation 2: The probabily is 0.1908.

Interpretation 1: The proportion is 34.16%

Interpretation 2. the probabilty is 0.3416.

36.

Interpretation 1. proportion is 33.09%

Interpretation 2. probability is 0.3309

Interpretation 1. proportion is 11.07%

Interpretation 2. probability is .1107