(a) We want to find the probability that is greater than 2500 x P(Z > 1) = 0.1587 from the normal table (b) > 2800 x P(Z > 1:6) = 0.0548 (c) < 1600 x P(Z < -0.8) = P(Z > 0.8) by symmetry = 0:2119 22. (a) P(Z>2) = .0228 or 2.28% will over £130 (b) (Z>1.33) = .0918 or 9.18% will spend over £120 (c) P(Z<-2) = .0228 or 2.28% will spend less than £70 (d) (100<x<130) = 50 2.28 – = 47.72% (e) For £115
(a) We want to find the probability that x is greater than 2500 P(Z > 1) = 0.1587 from the normal table (b) x > 2800 P(Z > 1:6) = 0.0548 (c) x < 1600 P(Z < -0.8) = P(Z > 0.8) by symmetry = 0:2119 22. (a) P(Z>2) = .0228 or 2.28% will over £130 (b) (Z>1.33) = .0918 or 9.18% will spend over £120 (c) P(Z<-2) = .0228 or 2.28% will spend less than £70 (d) (100<x<130) = 50 – 2.28 = 47.72% (e) For £115