probability that the persons IQ falls between 110 and 130 is 0.2286 .
<u>Step-by-step explanation:</u>
Step 1: Sketch the curve.
The probability that 110<X<130 is equal to the blue area under the curve.
Step 2:
Since μ=100 and σ=15 we have:
P ( 110 < X < 130 )=P ( 110−100 < X−μ < 130−100 )
⇒ P ( (110−100)/15< (X−μ)/σ<(130−100)/15)
Since Z = (x−μ)/σ , (110−100)/15 = 0.67 and (130−100)/15 = 2 we have:
P ( 110<X<130 ) = P ( 0.67<Z<2 )
Step 3: Use the standard normal table to conclude that:
P ( 0.67<Z<2 )=0.2286
Therefore, probability that the persons IQ falls between 110 and 130 is 0.2286 .
