If the quartile derivation of a series ia 60,the mean derivation of the series is​

To solve this exercise, you must apply the proccedure below:

 1. First, you must apply the formula for calculate the area of a semicircle, which is:

 A=πr²/2

 A is the area of the semicircle.
 π=3.14
 r is the radius of the semicircle

 2. The radius is:

 r=D/2
 r=30.77 feet/2
 r=15.385 feet

 3. When you substitute the values into the formula, you obtain:

 A=πr²/2
 A=(3.14)(15.385 feet)²/2
 A=371.61 feet²

 The area that will be painted grey is: 371.61 feet²