Question

assume that adults have IQ scores that are normally distributed with a mean of 100.6 and a standard deviation 24.8. Find the first quartile Q1, which is the IQ score separating the bottom 25% from the top 75%.

Answer 1

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the First Oncatile (Q1) be z XNN 100.6, Hence PIX<t] = 0.25 24-8) 27 p X - 100.6 24.8 KE-100.8 -) = Z 0.25 24.8 => z - 100.6 =-0.674 (From 2 table) 24.8 => t = 83.8848 8 3 - 88 (two decimal Rounded ed) cous)