Find the geometric mean between 9 and 11

To which set of numbers does the number –5 belong? select all that apply. integers natural numbers rational numbers real numbers whole numbers

Need on this geometry question. explain how you did it.

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%