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