Quality control reports for two production batches of biscuits are as follows:
Batch M: mean weight = 100 g, standard deviation = 1 g, range = 10 g
Batch N: mean weight = 100 g, standard deviation = 2 g, range = 4 g
Based on the information, which action is most advisable?
(a) Investigate Batch N because its higher standard deviation indicates the weights fluctuate widely across all biscuits.
(b) No investigation is required because both batches share the same mean and their spreads are within typical tolerance limits.
(c) Investigate possible outliers in Batch M because its large range suggests a few extreme biscuits.
(d) Investigate both batches since their different standard deviations show that neither run achieved identical consistency.