The production manager of Hinton Press is determining the average time needed to photograph one printing plate. Using a stopwatch and observing the platemakers, he collects the following times (in seconds):

Question

20.4 20.0 22.2 23.8 21.3 25.1 21.2 22.9 28.2 24.3
22.0 24.7 25.7 24.9 22.7 24.4 24.3 23.6 23.2 21.0

An average per-plate time of less than 23.0 seconds indicates satisfactory productivity. Should the manager be concerned

Answer 1

Ans