The following table gives the amount of time X, in seconds, by which an automated manufacturing process misses the designed completion time when performing a certain task. Negative values indicate early completion, and positive values late completion.

(a) Find the mean and the variance of X.

(b) On average, how do the completion times for this particular task compare with the designed completion times?

Transcribed Image Text:

r P(X = r) -1 .1 0 .2 1 .3 24 4