normal distribution

[kim270]

I was just wondering if someone could check this for me:

Intelligence Quotient (IQ) scores are approximately normally distributed with mean 100 and varience 400

Find the probability that a randomly selected person has and IQ score for between 80 and 130

Letx be IQ score

P(80<x<130)= p(-1<Z<1.5)
P(80<x<130)= (1-0.8413)+0.9332
P(80<x<130) = 0.7754

 

[Unco]

Not sure about your working but your answer is spot on!