Question
Assume that adults have IQ scores that are normally distributed with a mean of 100 and a standard deviation of 15. Find the probability that a randomly adult has an 10 between 110 and 125. Note first determine score for x_1 z=[x-mu] then use Table A-2 to determine the probability Answer____ Assume that adults have IQ scores that are normally distributed with mean al 100 and a standard of 15 Find the IQ score separating the top 25% (area under curve 7500) from the others Note: using Table A-2 (2 decimal places) x=mu+ 110 IQ 112 IQ 114 IQ 115 IQ
Explanation / Answer
5) Z1 = 110-100 / 15 = 0.666
Z2 = 125-100 / 15= 1.666
Probability that (0.66<z<1.66) =P(Z<1.66) - P(Z<0.66) 0.952203- 0.747486 = 0.204717
for probability that P(z)>0.25, z = 0.67449
Hence, x-100 /15 = 0.67449
or,x = 15*0.67449+100 = 110.11
hence, answer is A