Stat assignment

HW 2 Due Date: Oct, 02 Name……………………………………………….. ID……………………… 1 If IQs were perfectly normally distributed. (Assume what percentage of IQ scores would fall between? * 70 and 100? Using the z-score formula z = (x - μ) σ For x = 70 z = (70 - 100) 15 = -2 For x = 100 z = (100 - 100) 15 = 0 Using the z-table * P (z = -2) = 0.0228 * P (z = 0) = 0.5000 The percentage of IQs between 70 and 100 is: P (70 < x < 100) = P (z = 0) - P (z = -2) = 0.5000 - 0.0228 = 0.4772 About 47.72% of IQ scores fall between 70 and 100. * Less than 110? For x = 110 z = (110 - 100) 15 = 10 15 = 0.67 P (z = 0.67) = 0.7486 Thus, about 74.86% of IQ scores are less than 110. 2 Find the area under the stan...