Acorporation vp claims the average age of their senior managers is 48.8 years old. human resources decides to test this claim with a sample of 120 senior managers and finds their average age to be 49.5 years old with a standard deviation of 3.6 years. the level of significance used was 0.05

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.