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The iq of students in a certain college is assumed to be normally distributed with mean 100 and variance 25. If 3 students are selected at random, find the probability that all of them have iq between 102 and 110. (Given A(0.4)=0.4772 and A(2)=0.1554) |
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Answer» Given : The iq of students in a CERTAIN COLLEGE is assumed to be normally distributed with mean 100 and variance 25 . 3 students are selected at random To FIND : probability that all of them have iq between 102 and 110. Step-by-step explanation: mean 100 Variance = 25 Variance = (Standard deviation)² => (Standard deviation)² = 25 => Standard deviation = 5 Mean = 100 SD = 5 Z score = ( Value - Mean)/SD Z = (102 - 100)/5 => Z = 0.4 A(0.4)=0.4772 => 47.72 % data lies above 102 Z = (110 - 100)/5 => Z = 2 A(2)=0.1554 => 15.54 % data lies above 110 Data lies in between 102 & 110 = 47.72 - 15.54 = 32.18 % 0.3218 is the probability that a students selected have score between 102 & 110 now probability all three students selected have score between 102 & 110 = (0.3218)³ = 0.033 0.033 is the probability that all 3 students have score between 102 & 110 Learn more: Assume that adults have iq scores that are normally distributed with ... The mean length of mature whiting is 35 cm and the standard ... |
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