CCHS
Chapter 5
Section 5.4 Practice
Name _______________________________________________________ Date________ Period ____
Use the Standard Normal Distribution to find the z-score that corresponds to the given cumulative
area or percentile. If the area is not in the table, use the entry closest to the area.
1. 0.3594
2. 0.9671
3. 0.43
4. 0.8
5. P20
6. P83
Find the indicated z-score(s) indicated by the graph.
7.
8.
Area = 0.2776
9.
10.
Area = 0.8508
Mambou
Area on each end = 0.1251
Area = .1093
2/6/2016
CCHS
Use the Normal Distribution to answer the following questions. x    z
11. Papa Fred’s Pizza has found that the mean time to deliver a pizza is 21.2 minutes with a standard
deviation of 6.1 minutes. They want to have a guaranteed delivery time. In order to deliver 99% within
the guaranteed time you need to find the time represented by the 99th percentile. What is this value?
12. Students who score in the bottom 10% on a mathematics admission test at Greenville Tech are
required to take a remedial math course. If the average score is 78 with a standard deviation of 6, what
is the score that determines if a student does or does not take the remedial course?
13. John finds that there is a scholarship available to all persons scoring in the top 5% on the ACT test.
If the mean score on the ACT is 21 with a standard deviation of 4.7, what score does he need in order to
qualify for the scholarship?
Mambou
2/6/2016
CCHS
Practice
Chapter 6
Section 6.4
Name ___________________Keys_________ Date_February 6, 2016_ Period ____
Use the Standard Normal Distribution to find the z-score that corresponds to the given cumulative
area or percentile. If the area is not in the table, use the entry closest to the area.
1. 0.3594 Z = InvNorm(0.3594) = -0.36
2. 0.9671 Z = InvNorm (0.9671) = 1.84
3. 0.43
Z = InvNorm (0.43) = -0.18
5. P20
Z = InvNorm(0.2) = - 0.84
4. 0.8
Z = InvNorm (0.8) = 0.84
6. P83
Z = InvNorm (0.83) = 0.95
Find the indicated z-score(s) indicated by the graph.
7.
Z < InvNorm (0.2776) = -0.59
Area = 0.2776
9.
Z > InvNorm (1-0.8508) = -1.04
8.
Z < InvNorm (0.1251) = -1.15 and
Z > InvNorm (0.1251) = 1.15
Area on each end = 0.1251
10. Z > InvNorm (1-0.1093) = 1.23
Area = 0.8508
Area = 0.1093
Use the Normal Distribution to answer the following questions. x    z
11. Papa Fred’s Pizza has found that the mean time to deliver a pizza is 21.2 minutes with a standard
deviation of 6.1 minutes. They want to have a guaranteed delivery time. In order to deliver 99% within
the guaranteed time you need to find the time represented by the 99th percentile. What is this value?
  21.2 min   6.1 min Z  InvNorm(.99)  2.33
  z  x    z so 21.2  6.1* 2.33  x  21.3  6.1* 2.33
6.99 min  x  36 min
Mambou
2/6/2016
CCHS
12. Students who score in the bottom 10% on a mathematics admission test at Greenville Tech are
required to take a remedial math course. If the average score is 78 with a standard deviation of 6, what
is the score that determines if a student does or does not take the remedial course?
  78   6 Z  InvNorm(0.10)  1.28
x    z so x  78  6 * 1.28)
x  70.32
13. John finds that there is a scholarship available to all persons scoring in the top 5% on the ACT test.
If the mean score on the ACT is 21 with a standard deviation of 4.7, what score does he need in order to
qualify for the scholarship?
  21   4.7 Z  InvNorm(1  0.05)  1.65
x    z so x  21  4.7 *1.65 x  28.73
Mambou
2/6/2016