Topic 6 - GRAPHICAL DISPLAYS OF ASSOCIATION

6-1: Cars Fuel Efficiency ( cont. )

(a)

(b) Heavier cars tended to get worse fuel efficiency.

(c) negatively

(d) yes; there are many such pairs.

6-2: Guess the Association

(a) Students who did well on the first test tended to do well on the second, and those who did poorly on the first tended to do poorly on the second.
(b)

	Most strong	Moderate	Least strong
Negative	C	D	F
Positive	E	A	B

(c) (Asks for interpretation)

6-3: Marriage Ages ( cont. )

(a) yes; positive; fairly strong

(b) 2

(c) 16

(d) 6

(e) One can discover that for most of these couples, the husband is older than the wife.

6-4: Fast Food Sandwiches

(a)

A- roast beef
B - chicken
C - turkey

(b) There is a reasonably strong, positive association between a sandwich's serving size and its calories.

(c) Roast beef sandwiches tend to have more calories per serving size than do chicken and turkey sandwiches.

6-5: Space Shuttle O-Ring Failures

(a)

The scatterplot reveals a weak-to-moderate negative association between temperature and O-ring failures.

(b) The likelihood of O-ring failure appears to be greater at such a low temperature.

(c)

The association is much weaker in this case.

(d) (Asks for interpretation)

6-7 Air Fares

(a)

(b) Air fare is associated with distance.  Moderate, positive association.

(c) Atlanta and Chicago, Detroit and St. Louis