In an attempt to increase business on Monday nights, a restaurant offers free dessert with every dinner order.Before the offer, the mean number of dinner customers on Monday nights was 152.The following are the numbers of diners on a random sample of 12 Monday nights while the offer was in effect.

206169191152212139142151174220192153

Part (a) - 2 Points

Look at the above dot-plot of the data.Why does the plot suggest that it is okay to conduct a hypothesis test?

Part (b) - 6 Points

Test at the = 0.05 level whether or not the dessert promotion increasedthe mean number of dinner customers on Monday nights.Carry out and showthe 5 steps ofhypothesis testing as outlined inThe Framework of All Hypothesis Testingwithin this week's learning module.