Statistics 1060B

Solutions to Practice Problems for Week 5

3.11

The subjects of this experiment are the students and the factors involved are the length of the commercial and the number of times the commercial is repeated. The two treatments are a 30 second version of the commercial repeated 1, 3 or 5 times and a 90 second version of the commercial repeated 1, 3 or 5 times. Finally the response variables are the recollection of the ad, the students attitide toward the camera and the students intention to buy the camera.

3.21

From text:
``Make a diagram similar to Fig. 3.2 and 3.3 (in textbook), but with 4 branches (one for each colour) rather than 2 or 3. Assign labels 01 to 16, then choose two digits at a time from the table: use blue on poles 04, 09, 14, and 03; green on 10, 06, 11 and 16; white on 02, 07, 13, and 15; and yellow on the rest." (Moore & McCabe, 1998)

3.47

This poll is biased. There are a few factors. People who oppose handgun control are more likely to call because they feel stronger about the issue than those who support gun control. The response being voluntary is another factor. Many people just won't take the time to call. The fact that to vote you must call at a charge of 50 cents would not attract poorer people.

3.53

43 unlisted numbers would be a statistic and 52% of all L.A. phones being unlisted would be a parameter.

Jonathan Payne
January 27, 1999