Because of high production-changeover time and costs, a director of manufacturing must convince management that a proposed manufacturing method reduces costs before the new method can be implemented. The current production method operates with a mean cost of $220 per hour. A research study will measure the cost of the new method over a sample production period. (a) Develop the null and alternative hypotheses most appropriate for this study. H0: μ - Select your answer - $ Ha: μ - Select your answer - $ (b) Comment on the conclusion when H0 cannot be rejected. When H0 cannot be rejected, there - Select your answer - enough evidence to conclude that the proposed manufacturing method - Select your answer - costs. (c) Comment on the conclusion when H0 can be rejected. When H0 can be rejected, there - Select your answer - enough evidence to conclude that the proposed manufacturing method - Select your answer - costs.

Here, a director of manufacturing must convince management that a proposed manufacturing method reduces costs before the new method can be implemented. The current production method operates with a mean cost of $220 per hour.

a) The alternative and null hypotheses would be:

H0: μ ≥ 220

Ha: μ < 220

b) Comment on the conclusion when H0 cannot be rejected:

When we fail to reject the null hypothesis H0, there is not enough evidence to conclude that the mean cost can be reduced from $220. Therefore the manager's proposed method cannot be implemented.

c) Comment on the conclusion when H0 can be rejected:

When the null hypothesis, H0 is rejected, there is enough evidence to conclude that the mean cost can be reduced from from $220. Therefore the manager's proposed method can be implemented.