Answer:
The rational function that is graphed is B
Answer:

If we solve for k we can do this:




So then we have at last 75% of the data withitn two deviations from the mean so the limits are:


Step-by-step explanation:
We don't know the distribution for the scores. But we know the following properties:

For this case we can use the Chebysev theorem who states that "At least
of the values lies between
and
"
And we need the boundaries on which we expect at least 75% of the scores. If we use the Chebysev rule we have this:

If we solve for k we can do this:




So then we have at last 75% of the data withitn two deviations from the mean so the limits are:

