What is the radius of a ball with a surface area equal to 85 square inches?

To find the radius of a sphere when you know the surface area, you can use the formula for the surface area of a sphere:

S = 4 π r²

In this case, we have S = 85 square inches. We need to rearrange the formula to solve for the radius (r).

Starting with the formula:

85 = 4 π r²

First, divide both sides by 4π to isolate r²:

r² = &frac{85}{4π}

Now let’s calculate the right side:

Using π ≈ 3.14:

r² = &frac{85}{4 × 3.14} ≈ &frac{85}{12.56} ≈ 6.77

Next, take the square root of both sides to find r:

r ≈ √{6.77} ≈ 2.6

Rounding to the nearest tenth, the radius of the ball is approximately 2.6 inches.