Question 950089: IQ scores are normally distributed with mean =100 and standard deviation =16
a) What IQ represents the 15th percentile
b) What IQ represents the 75th percentile
c) What IQ represents the 98th percentile
d) What IQ represents the 22nd percentile
e) Find Q1 and Q3
f) Find the IQR of the IQs
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! IQ scores are normally distributed with mean =100 and standard deviation =16
a) What IQ represents the 15th percentile
Find the z-value with a left-tail of 0.15
invNorm(0.15) = -1.0364
---
Find the corresponding score: -1.0364*16 + 100 = 83.42
-----------------------
Comment: Same procedure for b,c,d, and e
-------------------------------
b) What IQ represents the 75th percentile
c) What IQ represents the 98th percentile
d) What IQ represents the 22nd percentile
e) Find Q1 and Q3
f) Find the IQR of the IQs
Ans:: Q3 - Q1 = 0.67*16+100-[-0.67*16+100] = 2*0.67*16 = 21.58
-------------
Cheers,
Stan H.
|
|
|
