I get how to find the volume of a sphere using 3.14 as Pi but I can't figure out how to use 22/7 the equation is 4/3 Pi rcubed the radius is 6 3/4 and PI is 22/7 help!

Since it is already known that the volume of a sphere is 4/3 Pi radius cubed, all that is left is to replace all the variables in the formula.

V = 4/3 Pi radius cubed

V = 4/3 * 22/7 * (6 3/4)^3

88/21 * (307 35/64) = 72171/56 = 1288 43/56

Don't forget to include the unit of the radius!