Recall again that Rind & Bordia (1996) investigated whetheror not drawing a happy face
on customers’ checks increased the amount of tips received by awaitress at an upscale
restaurant on a university campus. During the lunch hour a waitressdrew a happy,
smiling face on the checks of a random half of her customers. Theremaining half of the
customers received a check with no drawing (18 points).
The tip percentages for the control group (no happy face) are asfollows:
45% 39% 36% 34% 34% 33% 31% 31% 30% 30% 28%
28% 28% 27% 27% 25% 23% 22% 21% 21% 20% 18%
8%
The tip percentages for the experimental group (happy face) are asfollows:
72% 65% 47% 44% 41% 40% 34% 33% 33% 30% 29%
28% 27% 27% 25% 24% 24% 23% 22% 21% 21% 17%
This time, you are to perform a “hypothesis test†using the tipdata, answering each of
the questions below. For short-answer questions, be brief. However,you must give
enough detail to justify your answers. Single-sentence responseswill generally not
suffice, but do not exceed a paragraph for any given answer.
o. Considering both the probability value and effect sizemeasure, what
interpretations would you make about the findings? That is, whatare your
conclusions about the effects of leaving happy faces on checks?
