11. Jake scored a 94 on his last quiz, which was exactly 2 standard deviations above the
mean of his class. If the standard deviation was 3, what was the mean grade on the quiz?

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.