Suppose two points (xq, jo) and (X|, >]) are on a straightline with >-| ^ yc,. Two formulas are available to find the x-intercept ofthe line: xo)'i. (x, - xo)>>o x and x xq . 3'i - M Ji - Jo a. Show that both formulas are algebraically correct. b. Use the data (xq, yo) = (1-31, 3.24) and (xi, yi) = (1-93,4.76) and three-digit rounding arithmetic to compute the x-intercept both ways. Which method is better, and why?
Statistics – Baugh – Final Study Guide Solutions 1) For the discrete probability distribution: x 5 10 15 20 (L1) P(X = x) 20% 30% 40% 10% (L2) a) Find the mean, variance, and standard deviation. ux= 12.0 (.20 * 5) + (.30 * 10) + (.40 * 15) + (.10 * 20) = 12.0 = 21 2 2 2 2 (.20 * 5 )2+ (.30 * 10 ) + (.40 * 15 ) + (.10 + 20 ) = 5 + 30 + 90 + 40 = 165 – 12 = 21 = 4.5826 √21 = 4.5826 b) Find the cumulative probability: P( X 15) Less than or equal to 15 which is 5, 10, and 15 .20 + .30 +.40 = 0.90, 90% c) Find the expectation value: E[√X ] (.
