Answer:
Number of People having IQ higher than 135 = 1,298,460 Nos
Step-by-step explanation:
Approach 1 using Normal Distribution Tables:
As we know that for normal distribution z(x) = (x-Mu)/SD - Equation 1
Given Data:
Mean of IQ scores = Mu = 90
Standard Deviation in IQ scores = SD = 17
Let we assume that probability of having IQ scores less than or equal 135 = P(A)
The z for IQ scores of 135 may be calculated using equation 1 as under:
z(135) = (135-90)/17 = 2.6470 = 2.65 //After rounding off to two decimals
Using the Normal distribution tables we have:
P(A) = (P<=135) = 0.99598
As we know that:
Probability of having IQ scores more than 135 = 1 - Probability of having IQ scores less than or equal to 135
Probability of having IQ scores more than 135 = 1 - P(A)
Probability of having IQ scores more than 135 = 1 - 0.99598
Probability of having IQ scores more than 135 = 0.00402
As total population of country is equal to 323,000,000 Nos therefore number of people having IQ scores more than 135 = 0.00402 * 323,000,000
Number of people having IQ scores more than 135 = 1,298,460
Approach 2 using Excel or Google Sheets:
Probability of having IQ scores more than 135 = 1 - norm.dist(135,Mu,SD,Commutative)
Probability of having IQ scores more than 135 = 1 - norm.dist(135,90,17,1)
And then after multiplying with the total population of country we will get the number of people having IQ scores more than 135.
PS: The normal distribution tables are being attached for yours easiness.
