7.1

31.

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

Interpretation 1. 15.87% of people pay $44 or less for their monthly cell phone charge.

Interpretation 2. 84.13% of people pay $44.01 or more for their montly cell phone charge.

32.

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

Interpretation 1. 11.51% of refrigerators last 17 years or more.

Interpretation 2. 88.49% of refrigerators last 17 years or less.

33.

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

Interpretation 1. 2.28% of full term babies have birth weight of 2210 or more.

Interpretation 2. 2.28% of full term babies will have birth weights of 2210 or less.

34.

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

Interpretation 1. 4.96% of 10-year-old boys are 46.5 inches or shorter.

Interpretation 2. 95.04% of 10-year-old boys are 46.5 inches or taller.

35.

Interpretation 1. 19.08% of human pregnancies last 280 days or more.

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

Interpretation 1. The proportion of human pregnancies that last between 230 and 260 is .342.

Interpretation 2. The probability that a human pregnancie will last between 230 and 260 days is 34.16%.

36.

Interpretation 1. .331 of the time Elen can fill her gass tank with 26 miles per gallon.

Interpretation 2. The probability that Elen can fill her tank with 26 miles per gallon is 33.09%.

Interpretation 1. Elen can fill her gas tank up with 18 to 21 miles per gallon 11.07% of the time.

Interpretation 2. the probability that Elen randomly fills her tank with between 18 to 21 is .111.

7.2

5.

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

7.

  1. .9987.
  2. .9441.
  3. .9115.
  4. .0009.

9.

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

11.

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

13. -2.28.

15. .67.

17. -.575.

33. 40.62 is the 9th percentile.

35. 56.16 is at the 81st percentile.

37.

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

  1. .1587.
  2. .1587.
  3. .4772.
  4. yes .0.0013.

39.

  1. .8658.
  2. .0132.
  3. .7019.
  4. .1230.
  5. 1475 chocolate chips in a bag is at the 96th percentile.
  6. 1050 chocolate chips in a bag is at 4th percentile.

41.

  1. .4013.
  2. .1587.
  3. .7590.
  4. .1894.
  5. .0951.
  6. yes .0043.

43.

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

45.

  1. yes mean of 0 implies the spreads are accurate
  2. .3228.
  3. .4286.

47.

  1. 17th percentile for incubation time is 20 days.
  2. from 19 to 23 days make up the middle of 95% of fertilitzed eggs.

56. SAT you have a z-score of 1.02 and on ACT you get a z-score of .961 and because 1.02> .961 then you would do better on the SAT with a score of 1240 than an ACT score of 26.