Test 1 Review
A computer manufacturer attaches a special serial number from 1 to 1000 to each disk drive
that is manufactured during a week. A random sample of 20 disk drives is to be selected and
inspected for quality and effectiveness.
o Density Curve A curve that displays the overall pattern of the distribution, has an
area of exactly 1 square unit underneath it, and is on or above the horizontal axis
o Percentile Percent of the distribution that is at or
The Normal Distributions
2.1 There are many correct drawings. Here are two possibilities:
2.2 (a) The area under the curve is a rectangle with height 1 and width 1. Thus the total area under
thecurve= 1 X 1 = 1.
(b) 20%. (The region is