Question

The manager of a door-making company would like to estimate the amount of time it takes for a piece of wood to be moved, cut, and packaged at two different plants. At Plant A, the manager observed 21 pieces that processed with an average time of 14.2 minutes and standard deviation of 2.6 minutes. At the second plant, the manager observed 19 pieces with an average time of 13.1 minutes with a standard deviation of 1.9 minutes.

a. Test whether there is a difference between mean process times of Plants A and B with an assumed α = 0.1. State your conclusion properly with context.

b. What three assumptions are required to perform the above test?

c. Using the above information and α = 0.1 significance level, test to see if the plants have different variability. State your conclusion properly with context.

Answer 1