7.1

31.

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

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

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

32.

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

Interpretation 1. 11.51% of refrigerators are kept for 17 or more years

Interpretation 2. The probability that a randomly selected refrigerator has been kept for 17 or more years is .1151

33.

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

Interpretation 1. Of all full term babies, 2.28% of them have a birth weight greater than 4410 grams

Interpretation 2. The probability that a randomly selected, full term baby weighs 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 for males who are less than 46.5 inches and also 10 years old is .0496

Interpretation 2. The probability that a 10 year old male is less than 46.5 inches when chosen randomly is .0496

35.

Interpretation 1. .1908 is the proportion of pregnancies that last more than 280 days

Interpretation 2. The probability that a random human pregnancy lasts longer than 280 days is .1908

Interpretation 1. The proportion of 230 to 260 day pregnancies is .3416

Interpretation 2. The probability that a random pregnancy would last between 230 to 260 days is .3416

36.

Interpretation 1. The proportion of times Elena will get more than 26 miles per gallon is .3309

Interpretation 2. The probability that a random refuel will give Elena at least 26 miles per gallon is .3309

Interpretation 1. The proportion of times Elena will get 18 to 21 miles per gallon is .1107

Interpretation 2. The probability that a random refuel will give Elena 18 to 21 miles per gallon is .1107

7.2

5.

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

7.

  1. A= .9987
  2. A= .9441
  3. A= .0376
  4. A= .0009

9.

  1. A= .9586
  2. A= .2088
  3. A= .8479

11.

  1. A= .0456
  2. A= .0646
  3. A= .5203

13. z= -1.28

15. z= .67

17. z1= -2.575; z2= 2.575

33. x= 40.62 is in the 9th percentile

35. x= 56.16 is in the 81st percentile

37.

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

  1. Expect 16 eggs to incubate for less than 20 days
  2. Expect 16 eggs to incubate for more than 22 days
  3. Expect 48 eggs to incubate for in between 19 and 21 days
  4. Expect 1 egg (of 1000) to incubate in less than 18 days

39.

  1. P= .8657
  2. P= .0132
  3. .7019 of chocolate chip bags haev more than 1200 chocolate chips
  4. .1228 of chocolate chip bags have less than 1125 chocolate chips
  5. A bag with 1475 chocolate chips is in the 96th percentile
  6. A bag with 1059 chocolate chips is in the 4th percentile

41.

  1. .4013 pregnancies last over 270 days
  2. .1587 pregnancies last less than 250 days
  3. .7590 pregnancies last between 240 and 280 days
  4. P= .1894
  5. P= .0951
  6. Yes, about 4 births out of 1000 would be preterm since .0043 of births are preterm

43.

  1. .0764 rods are smaller than 24.9cm
  2. .0324 rods will be discarded
  3. The plant mananger would get rid off 162 out of the 5000 manufactured rods
  4. The plant mananger should make 11804 rods to satisfy the order