Percent increase = ((new number - original number) / (original number)) x 100.
percent increase = ((3000 - 2500) / 2500)) x 100 =
(500 / 2500)....x 100 =
0.2 x 100 =
20% increase <====
A. z = 0.74
The z-score of 0.74 translates to a percentile of 0.77035. Hence, the area under the standard normal curve to the left of z-score 0.74 is ~0.77.
b. z = -2.16
This z-score translates to a percentile of 0.015386 which is also the numerical value of the area under the curve to the left of the z-score
c. z = 1.02
The percentile equivalent of the z-score above is 0.846. The area is also 0.846.
d. z = -0.15
The percentile equivalent and the area is equal to 0.44.