Chapter MCQ Test 2 — Correlation
10 Questions • 12 min • Chapter MCQ
12:00
Question 1 of 10
As a household's income rises, its consumption also rises. The correlation between income and consumption is:
Positive
Negative
Zero
Perfect negative
Explanation: Both move in the same direction, so the correlation is positive.
Question 2 of 10
A scatter diagram whose dots lie almost exactly on an upward straight line indicates:
Strong (near-perfect) positive correlation
Negative correlation
No correlation
A pie chart
Explanation: The closer the dots hug an upward line, the nearer r is to +1.
Question 3 of 10
For data where Σ(dx·dy) is negative while Σdx² and Σdy² are positive, the value of r is:
Negative
Positive
Exactly zero
Greater than 1
Explanation: The denominator is always positive, so the sign of r follows the sign of Σ(dx·dy).
Question 4 of 10
Two examiners rank 5 students and get ΣD² = 0. The rank correlation R is:
+1
0
−1
0.5
Explanation: R = 1 − (6×0)/(5×24) = 1 − 0 = +1 — the examiners agree perfectly.
Question 5 of 10
Spearman's method is chosen over Pearson's when the data are about qualities like beauty or honesty because such qualities can only be:
Ranked, not exactly measured
Added together
Drawn as pies
Ignored
Explanation: Qualities have no exact numerical scale, so we rank them and use Spearman's R.
Question 6 of 10
The number of umbrellas sold and the amount of rainfall show high positive correlation. The most likely reason is:
Rain genuinely drives umbrella sales (a real relationship)
Umbrellas cause rain
Pure coincidence with no link
A third hidden factor only
Explanation: Here the link is real and causal — but the chapter still warns that correlation alone does not, by itself, prove causation.
Question 7 of 10
An r of −0.92 between two variables means they are:
Strongly inversely related
Weakly related
Unrelated
Perfectly positively related
Explanation: A value close to −1 shows a strong inverse (negative) relationship.
Question 8 of 10
Karl Pearson's r can be distorted by extreme values because it is based on:
Deviations from the mean
Ranks
The mode
Cumulative frequency
Explanation: Because r uses the mean, an extreme value (which shifts the mean) can distort r.
Question 9 of 10
If two judges rank items in exactly the opposite order, the rank correlation R will be:
−1
+1
0
0.5
Explanation: Completely reversed rankings give perfect negative agreement, R = −1.
Question 10 of 10
A scatter of dots with no upward or downward pattern indicates that r is close to:
0
+1
−1
10
Explanation: No pattern means no correlation, so r is near 0.