
Questions with Answer Page

 1. State the area under the standard normal curve
 between zscores of 0 and 1.42.
42.22% or .4222

 2. Given the standard normal distribution, compute
 p(z is within 1.42 standard deviations of the mean),
 p(1.42 < z < 1.42). 84.44% or .8444

 3. Given the standard normal distribution, find the zscore such that
 p(z is within __ standard deviations of the mean) = 95%.
 Half of 95% is 47.50%, and matches a zscore of 1.96, the answer.

 4. Find, to two decimal places accuracy, the boundaries
 in the standard normal distribution, such that
 p(z is within __ standard
deviations of the mean) = 74.98%.
 Half of 74.98% is 37.49%, and matches a zscore of 1.15, the answer.

 5. Using the zscores in the above table, state the lowest zscore
 which is in the top 90% of all scores.
 The zscore required matches an area of 40%, 90%  50%. The lowest zscore is 1.29,
matching an area of 40.15%.

 6. Using the zscores in the above table, state the lowest zscore
 which is in the top 85% of all scores.
 The zscore required matches an area of 35%, 85%  50%. The lowest zscore is 1.04,
matching an area of 35.08%.

 7. Compute:
 p(2.2 < z < 2.35). answer is .45%, work is at

 8. Compute,
 given a normal distribution,
= 3 and s = 0.4,
 p(2 < x < 4). answer is 98.76%, work at
