sandy wrote:
Attachment:
Capture.PNG
The graph represents the normally distributed scores on a test. The shaded area represents approximately 68% of the scores.
Quantity A |
Quantity B |
The mean score on the test |
\(550\) |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Given: The shaded area represents approximately 68% of the scores.
In other words, 68% of the area under the curve is shaded.
However, even though it LOOKS like the shaded area is SYMMETRICAL about the mean, we aren't told that. So we cannot assume that that is the case. If the shaded area IS symmetrical about the mean,....
....then the mean is 550, in which case the two quantities are EQUAL.
However, it could also be the case that the shaded area is NOT symmetrical about the mean
For example, in the above diagram, 68% of the area under the curve is shaded. HOWEVER, it is not symmetrical about the mean.
In this case, the mean could be something like 530, in which case Quantity B is greater than Quantity A
Answer: D
Cheers,
Brent
_________________
Brent Hanneson – Creator of greenlighttestprep.com
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