Problem 48

  1. Normal model

Conditions of 10% and random are met, probably (unclear)

4.7% chance

  1. 0.95^3 = 86.3%

  2. N(10.2, 0.12/sqrt(3))

0.18% chance

  1. N(10.2, 0.12/squrt(24))

near 0

Problem 50

  1. we cant apply the normal model to the individual since the model wwould not fit a skwed distribution. Therefore our answer would be far away from the empiracal actual value

  2. We cannot know, since we havent yet learned how to deterime whether quanitivative values are enough to representative

  3. Probably, if this is a representative number of people and fits out conditions for using the normal model through the central limit thorem.

Problem 52

  1. N(9984, squrt(312*20^2))

N(9984, 353)

0.48

  1. N(9984, 353)

$ 9531

Problem 54

  1. N(47,6)

30.8 % chance of more than 50 pounds

  1. Expect a differnce of 4

sd = 7.8

69.6 %

  1. N(43,1.1180)

0.037

  1. N(4, 2.203)

0.325 chance for 10 asheyers to average 5 pounds higher