Question 1.101

1.101 Use Table A or software.

Consider a Normal distribution with mean 200 and standard deviation 20.

  1. Find the proportion of the distribution with values between 190 and 220. Illustrate your calculation with a sketch.
  2. Find the value of such that the proportion of the distribution with values between and is 0.75. Illustrate your calculation with a sketch.

1.101

(a) Between -0.5 and 1. 0.5328. (b) corresponds with the 12.5 percentile . corresponds with the 87.5 percentile . Solving gives .