The operating characteristic curves of three single sampling plans X, Y and Z with the same lot size and acceptance number are shown in the figure.
Considering the above operating characteristic curves, the correct relationship of the plans with respect to sample size is
1
Sample size of X < sample size of Y < sample size of Z
2
Sample size of X = sample size of Y = sample size of Z
3
Sample size of X > sample size of Y > sample size of Z
4
Sample size of X > sample size of Y < sample size of Z