Problem 3.2 Better Supply Co. manufactures and assembles wooden tables in several plants in Jakarta. Plant 2 produced 150 wooden tables every week. Plant 2 follows a normal probability distribution with a mean of 300 and a standard deviation of 30. Recently, because of market expansion, new production methods have been introduced and new employees were hired. The head manager of manufacturing department would like to investigate whether there has been a change in the weekly production of the wooden tables. Is the mean number of tables produced by Plant 2 different from 230 at the .05 significance level