Answer:



And in the figure attached we see the limits with the percentages associated.
Step-by-step explanation:
For this case we know that the random variable of interest is the scores on a test given to all juniors in a school district follows a normal distribution with the following parameters:

For this case we know from the empirical rule that within one deviation from the mean we have approximately 68.2% of the data, within 2 deviations from the mean we have 95% and within 3 deviation 99.7%
We can find the limits and we got:



And in the figure attached we see the limits with the percentages associated.
Answer:3
Step-by-step explanation:
10-4/2-0 = 6/2 = 3
31. +
34. -
To figure out more, just solve the known problem, and then go over what the answer would be to the unknown one until you find the answer that makes it true.
12.347
- 9.432
------------
2.915
The answer is:
D. 2.915 kilometers