Recall that the formula for the volume of a sphere of radius R is given by:
[tex]\text{Volume}=\frac{4}{3}\pi\cdot R^3[/tex]
Notice that you are given the diameter of the sphere, and not the radius, so make sure we divide by two the measure of the diamtere in order to find the radius:
Radius = 4.2 cm / 2 = 2.1 cm
So we use this value in the above formula to find the volume:
[tex]\text{Volume}=\frac{4}{3}\pi\cdot(2.1)^3=38.772[/tex]
So we round the answer as requested to one decimal as shown below
Volume = 38.8 cm^3
