So its a little quiz i am giving brainiest and a lot of potions look at it TYSM! 30 FRECKING PONITS

Aregression was run to determine if there is a relationship between hours of tv watched per day (x) and number of situps a person can do (y). the results of the regression were: y=ax+b a=-0.662 b=30.418 r2=0.703921 r=-0.839

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

The radius of a sphere is 3 inches. which represents the volume of the sphere?