Dean Chalmers Cambridge International AS & A Level Mathematics: Probability & Statistics 2 Worked Solutions Manual f (t) 1 11 0 22 t f (x) 0.4 0 2.5 5 x f (t) 1 4 0 6 10 t f (x) 1 4 0 3 7 11 x 90 t f (t) 1 90 0 Approximate distribution of meansf or samples fo size 40. 1 µ = 2.0 and σ 2 = 3000 f (x) 22 0.9969 0.0031 2.0 2.05 X(40) Approximate distribution of meansf or samples fosize 20. 1 µ = 2.0 andσ 2 = 1500 f (x) 22 0.974 0.026 2.0 2.05 X(20) f(t) 0.5 0.4 0.3 0.2 0.1 0 0.5 Time (t mintues) 3 t