1a. A state administered standardized reading test is given to eighth grade stud

Question

1a.

A state administered standardized reading test is given to eighth grade students. The scores on this test for all students statewide have a normal distribution with a mean of 546 and a standard deviation of 76. A local Junior High principal has decided to give an award to any student who scores in the top 10% of statewide scores.

How high should a student score be to win this award?

Give your answer to the nearest integer. For help on how to input a numeric answer, please see the instructions for entering numeric response

1b.

The Mental Development Index (MDI) of the Bayley Scales of Infant Development is a standardized measure used in longitudinal follow-up of high-risk infants. The scores on the MDI have approximately a normal distribution with a mean of 100 and standard deviation of 15. What proportion of children have MDI of at least 88?

Explanation / Answer

we have to analyse the students who are top 10% scorers.

From Normal probability table, P( z > 1.28)= 0.10
That is, the z score such that 10 % are above it and 90 % are below it is 1.28.
z= (x-mean) / sd
1.28 = (x- 546) / 76
x= (1.28)(76)+546

=643.28

student should score atleast 643.28 to win this award.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

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