Which expression is equivalent to 3 square root2y3×7 square root18y, if y> 0?

Given the following sampling distribution of one mean with a sample size 49, from a normally distributed population, find the population standard deviation, o.79828588912497

Two cyclists 84 miles apart start riding toward each other at the samen time. one cycles 2 times as fast as the other. if they meet 4 hours later what is the speed (in miles) of the faster cyclists

Determine which expressions represent real numbers and which expressions represent complex number. asaaap! plis!