E) 12 minutes
A normal curve has approximately 95% of graph between mean - 2sd and mean + 2sd
So 95% of the times will be between 0 and 12 minutes. 6 - 2x3 to 6 + 2x3
2.5% will take over 12 minutes
Strangely 2.5% will also take less than 0 minutes to process which shows the normal curve is not perfect in this example.
If its diameter is 443 square inches, then its circumference is:
443 π square inches, as C=πd.
Surface area is the total area of the surface. A cube has 6 surface, and each surface is the same. Each surface is a 11 by 11 square. Therefore there will be 6 11in. x 11in. surfaces. The math would be 11x11x6 =726.