Question

a. What is the distribution of X? X ~ N(,)

b. Find the probability that a randomly selected person's IQ is over 107.  Round your answer to 4 decimal places.

c. A school offers special services for all children in the bottom 3% for IQ scores. What is the highest IQ score a child can have and still receive special services? (Note: Use the closest value in your z table). Round your answer to 1 decimal place.

d. Find the Inter Quartile Range (IQR) for IQ scores. Round your answers to whole numbers.
Q1: 
Q3: 
IQR: 

Answer 1

ms. Mean (M) = 120 std devo) = 15 107-120 5 a) XNN (120, 15) b) p (x > 107) = P(x-m 107-120 ) Plz>-0.87) = P125-0.87) = 1-0.19215 = (0.8079] 2 P(xx) = 0.03 P ( x 7-139 -0.03) p[201130)-003 From standard nomal table, 1-120 1.985 -> a = 91.73 1) P(x<*) - 0,25 -> P/X4< 9120 ) - 0,25 812<*-120) = 0.25 from standard normal table, -120 = -0.67 0 = a (109.95- 110 P/2LX - 120 ) = 0,75 - x-120 = 0.67 B3 = ? = (130.05) - (130) 15

Inter quartile vange (PQR) = Oz-8 = 150-110 - (20