In an attempt to increase business on Monday nights, a restaurant offers a free dessert with every dinner order. Before the offer, the mean number of dinner customers on Monday was 150.

Following are the numbers of diners on a random sample of 12 days while the offer was in effect.

a. Following is a boxplot for these data. Is it reasonable to assume that the conditions for performing a hypothesis test are satisfied? Explain.

b. Can you conclude that the mean number of diners increased while the free dessert offer was in effect? Use the α = 0.01 level of significance.

Transcribed Image Text:

206 169 191 152 212 139 142 151 174 220 192 153