If the square root covers both numbers do i add the square roots of the numbers

Your friend swims on the school team. in his first four races, his times are 24.7, 23.5, 25.6, and 27.2 seconds. which time listed for his next race would make the range larger?

Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test?

Subscriptions to a popular fashion magazine have gone down by a consistent percentage each year and can be modeled by the function y = 42,000(0.96)t. what does the value 42,000 represent in the function?