6.22 In each case, sketch the two specified normal curves on the same set of axes ...

     6.22 In each case,   sketch the two specified normal curves on the same set of axes   a. A normal curve with u = 20 and σ = 3,   and a normal curve with u = 20 and σ = 6   b. A normal curve with u = 20 and σ = 3,   and a normal curve with u = 30 and σ = 3   c. A normal curve with u = 100 and σ =   10, and a normal curve with u = 200 and σ = 20