An X- bar and R chart was prepared for an operation using twenty samples with five pieces in each sample X-bar was found to be 33.6 and R-bar was 6.20. During production, a sample of five was taken and the pieces measured 36, 43, 37, 25, and 38. At the time, this sample was taken
a. Both average and range were within control limits
b. Neither average not range were within control limits
c. Only average was outside control limits
d. Only the range was outside control limits