Which number is a perfect square? 7, 25, 66, 27?

Which number produces a rationale number when multiplied by 1/5

How do you create a data set with 8 points in it that has a mean of approximately 10 and a standard deviation of approximately 1?

Parabolas y=−2x^2 and y=2x^2 +k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.