TOPIC 2 EXERCISE
1
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rs e Topic 2 Exercises
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Shanice S. Roseborough
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Grand Canyon University: PSY-520
aC s
vi y re
April 29, 2020
ed d
ar stu
is
Th
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This study source was downloaded by 100000828872084 from CourseHero.com on 07-10-2021 20:59:46 GMT -05:00
https://www.coursehero.com/file/63126738/Topic-2-Exercise520docx/
, TOPIC 2 EXERCISE
2
Chapter 5
5.11 Finding Proportions Scores on the Wechsler Adult Intelligence Scale (WAIS) approximate
a normal curve with a mean of 100 and a standard deviation of 15. What proportion of IQ scores
are WAIS mean = 100; standards deviation = 15
a. Above Kristen’s 125?
µ = 100 ; ơ = 15
X−μ 125−100
z= = = 25/15 => z = 1.67 looking at table A
a
, it gives us a
σ 15
value of C = 0.0475.
b. Below 82
82−100 −18
z= = = -1.2, so z value of -1.2 gives us a C value of 0.1151
m
15 15
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co
c. Within 9 points of mean
eH w
z = 9/15 = 0.6
o.
z = (-9)/15 = -0.6, so B value of z = 0.6 is 0.2257, but it can be in positive or negative
rs e
direction so we need to add the two. 0.2257 + 0.2257 = 0.4514
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o
d. More than 40pts from mean
aC s
z = 40/15 = 2.67 or -2.67
vi y re
so if z = 2.67 then c value is 0.0038; but it is asking for more than 40pts so we do 1-
0.0038 = 0.0076. So 0.0076 is the answer.
ed d
ar stu
5.13 Finding Scores
Mean = 100; standard deviation = 15
is
a. Upper 2% to the right and 98% to the left. C = 0.020 and z value is 2.06
Th
X = µ + z (ơ)
X = 100 + 2.6 (15)
X = 130.90
sh
b. Lower 10% z= 1.29
x= 100 + (-1.29)(15)
x = 80.65
c. Upper 60% ; which means there is 40% is the other direction; but it is only 10% from 50.
We will use c = 0.10 and z = 1.29 but positive
This study source was downloaded by 100000828872084 from CourseHero.com on 07-10-2021 20:59:46 GMT -05:00
https://www.coursehero.com/file/63126738/Topic-2-Exercise520docx/
1
m
er as
co
eH w
o.
rs e Topic 2 Exercises
ou urc
Shanice S. Roseborough
o
Grand Canyon University: PSY-520
aC s
vi y re
April 29, 2020
ed d
ar stu
is
Th
sh
This study source was downloaded by 100000828872084 from CourseHero.com on 07-10-2021 20:59:46 GMT -05:00
https://www.coursehero.com/file/63126738/Topic-2-Exercise520docx/
, TOPIC 2 EXERCISE
2
Chapter 5
5.11 Finding Proportions Scores on the Wechsler Adult Intelligence Scale (WAIS) approximate
a normal curve with a mean of 100 and a standard deviation of 15. What proportion of IQ scores
are WAIS mean = 100; standards deviation = 15
a. Above Kristen’s 125?
µ = 100 ; ơ = 15
X−μ 125−100
z= = = 25/15 => z = 1.67 looking at table A
a
, it gives us a
σ 15
value of C = 0.0475.
b. Below 82
82−100 −18
z= = = -1.2, so z value of -1.2 gives us a C value of 0.1151
m
15 15
er as
co
c. Within 9 points of mean
eH w
z = 9/15 = 0.6
o.
z = (-9)/15 = -0.6, so B value of z = 0.6 is 0.2257, but it can be in positive or negative
rs e
direction so we need to add the two. 0.2257 + 0.2257 = 0.4514
ou urc
o
d. More than 40pts from mean
aC s
z = 40/15 = 2.67 or -2.67
vi y re
so if z = 2.67 then c value is 0.0038; but it is asking for more than 40pts so we do 1-
0.0038 = 0.0076. So 0.0076 is the answer.
ed d
ar stu
5.13 Finding Scores
Mean = 100; standard deviation = 15
is
a. Upper 2% to the right and 98% to the left. C = 0.020 and z value is 2.06
Th
X = µ + z (ơ)
X = 100 + 2.6 (15)
X = 130.90
sh
b. Lower 10% z= 1.29
x= 100 + (-1.29)(15)
x = 80.65
c. Upper 60% ; which means there is 40% is the other direction; but it is only 10% from 50.
We will use c = 0.10 and z = 1.29 but positive
This study source was downloaded by 100000828872084 from CourseHero.com on 07-10-2021 20:59:46 GMT -05:00
https://www.coursehero.com/file/63126738/Topic-2-Exercise520docx/
