Plz help me solve for x and y

What is the radius of a circle with an area of 78.5 cubic inches? use 3.14 for pie

Do one of the following, as appropriate: (a) find the critical value z subscript alpha divided by 2 , (b) find the critical value t subscript alpha divided by 2 . 99%; nequals 17; sigma is unknown; population appears to be normally distributed.

Adriana had a garden where he measured the height of a corn plant. what. on the first day, it was 145 cm tall. after 2 weeks is grew by 23 cm. what is the height of the corn plant