Steve has one semester left in his MBA program and is looking at paying back some hefty student loans. Even though he has had to borrow money to complete the program, he's decided it was a worthwhile investment.

Nonetheless, Steve would like to repay some of his loans before graduating, if at all possible. He has recently taken entrepreneurial and small-business classes and has decided to pet some of this knowledge to work. He suspects that a number of his fellow students would be willing to shell out a few bucks for school memorabilia.

Since summer is right around the corner, Steve is pretty sure that he can make some money by selling t-shirts to students on campus. Informal conversations with people in the hallways have given him some ideas about popular t-shirt designs. He decides to narrowed down the possibilities to 2. He's given sketches to a local t-shirt printing company, and they have made two prototype shirts.

At this stage, He has no idea about the relative demand for the two t-shirt designs. If he's going to all the trouble and expense of having the shirts made up, it would be useful to know which of the two shirts is more popular The two shirts look something like this:

1) The red shirt has a scoop neck, and is made of 100% cotton. On the back of the shirt is a logo of the school. Under the logo are the words, "PARTY TIME at JC UNIVERSITY !" Steve suspects that this shirt will mostly appeal to the party -goers.

2) The other shirt is more conservative. It is a white, button-placket, collared t-shirt made of 50% cotton and 50% synthetic materials. This shirt has a simple, and small, version of the school logo on the upper righthand section of the front of the shirt. Steve has decided to gauge the relative markets for his two t-shirts by running a quick survey.

With permission from the student government, he has set up a table in the student union. The two prototype shirts are there for inspection, along with a survey designed to gauge people's reactions to the two shirts. He has a big sign over the table offering a free soft drink to all participants to induce people to stop by the table and par ticipate in the survey. On the corner of his table is a big cardboard box with a slit in the top. Students are instructed to put their completed questionnaires in the box, thereby guaranteeing anonymity of the responses The actual survey is shown below. The data set is on the accompanying CD in the file named T-SHIRTS

1) Evaluate the Sampling design done by Steve.

2) How would you judge the quality of the survey instrument?

VARIABLE : LABEL GENDER Female =1, male =2. GPA Current grade point verage on the 4-point scale. PREFER Preference of red or white shirt (1,2= red; 3= neutral; 4,5 = white). AGE Age in years at the time of the survey. INCOME Gross annual income for 1993. HANDED Left-handed (=1 ) or right-handed (=2) or ambidextrous (=3)