For eight consecutive working days, the number of defective pieces produced by two small workshops was recorded as follows:
Workshop A: 3, 4, 2, 5, 4, 6, 3, 5
Workshop B: 2, 5, 4, 7, 6, 2, 8, 4
a. (i) Find the mean number of defective pieces for each workshop.
b. (ii) Calculate the standard deviation of the defective counts for each workshop.
c. (iii) Which workshop exhibits more uniform quality control? Give a brief justification based on your calculations.