Question

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.

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

Dot plot.xlsx ** CANNOT OPEN**

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 α = 0.05 level whether or not the dessert promotion increased the mean number of dinner customers on Monday nights. Carry out and show the 5 steps of hypothesis testing as outlined in The Framework of All Hypothesis Testing within this week's learning module.

Answer 1

(a)

Dot plot looks like symmetric(normal), so that we can use t test for testing the hypothesis.