A woodworker is concerned about the quality of the finished apperance of her work. in sampling units of a split willow hand woven basket, she has found the following number of finish defects in 10 unit sampled: 4, 0, 3, 1, 2, 0, 1, 2, 0, 2.
a) calculate the average number of defects per basket
b) if 3 sigma control units are used calculate the lower control limit, center line, and upper control limit