TWOla Bassociated with the score(s) given in the items above What column (B. B:

Question

TWOla Bassociated with the score(s) given in the items above What column (B. B: CorC'in Table A do you need to use to find the proportion requested in each item Can you find the proportion directly in the column in the table or do you have to use additional information to find the proportion? What additional information do you need to know or need to understand in order to find the proportion requested? Given a normal curve with a mean of 55 and a standard deviation of & find the following a- b. c. d. e· The scores associated with the upper 20% of the population The scores associated with the middle 80% of the distribution The scores assocated with the most extreme 5% of the population The scores associated with the lower 10% of the population-q The scores associated with the lower 60% of the population Considerations In drawing a normal curve, what target area should be shaded for each item above?

Explanation / Answer

Ans:

Given that

a)upper 20% means that

P(Z>=z)=0.2

P(Z<=z)=1-0.2=0.8

z=0.8416

x=55+0.8416*8=61.73

scores above 61.73 are the top 20%.

b)z value for middle 80% is 1.28

lower limit=55-1.28*8=44.76

upper limit=55+1.28*8=65.24

c)P(Z>=z)=0.05

P(Z<=z)=1-0.05=0.95

z=1.645

x=55+1.645*8=68.16

above 68.16 are the most extreme 5% scores.

d)P(Z<=z)=0.1

z=-1.282

x=55-1.282*8=44.74

Scores lower than 44.74 are the lower 10%

e)P(Z<=z)=0.6

z=0.2533

x=55+0.2533*8=57.03

Scores lower than 57.03 are the lower 60% scores.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.