SOLUTION: Questions 24-25 The scores of a standardized IQ test are normally distributed with a mean score of 100 and a standard deviation of 15. Question 24 Find the probability that a

Algebra ->  Statistics  -> Describing-distributions-with-numbers -> SOLUTION: Questions 24-25 The scores of a standardized IQ test are normally distributed with a mean score of 100 and a standard deviation of 15. Question 24 Find the probability that a      Log On


   

Question 1197517: Questions 24-25
The scores of a standardized IQ test are normally distributed with a mean score of 100 and a standard deviation of 15.
Question 24
Find the probability that a randomly selected person has an IQ score higher than 105.
Question options:
0.9522

0.3694

-1.15

0.6306
Question 25
A random sample of 55 people is selected from this population. What is the probability that the mean IQ score of the sample is greater than 105?
Question options:
0.0067

0.3694

0.6306

0.9933

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!

Hi
Question 24
z+=blue+%28x+-+mu%29%2Fblue%28sigma%29 ,  z = 5/15
P(x>105) = 1 - P(x ≤ 105) = 1 - P( z ≤ 1/3) = .3694
  
Question 25
 z+=blue+%28x+-+mu%29%2Fblue%28sigma%2Fsqrt%28n%29%29
 P(sample mean > 105) = .0067  
Wish You the Best in your Studies.