0.249 in fraction form

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?

What is always true about a positive integer raised to a negative odd power?