The ratio of the circumference to the diameter is defined as pi
pi=circumference/diameter
that is how they got pi
in this question it woul be 15.7/5 which would be 3.14,
c=2pir
a=pir^2
c=2pir=16pi
divide both sides by 2pi
r=8
a=pir^2
a=pi8^2
a=pi64
a=64pi in²
Answer:

Step-by-step explanation:

+8n +8n

Answer:
use formaul
Step-by-step explanation:
Answer:
Point estimate for the population variance = 3.92 *
.
Step-by-step explanation:
We are given that a sample of 5 strings of thread is randomly selected and the following thicknesses are measured in millimeters ;
X X -
1.13 1.13 - 1.188 = -0.058 3.364 * 
1.15 1.15 - 1.188 = -0.038 1.444 *
1.15 1.15 - 1.188 = -0.038 1.444 * 
1.24 1.24 - 1.188 = 0.052 2.704 * 
1.27 1.27 - 1.188 = 0.082 <u> 6.724 * </u>
<u> </u>
<u>= 0.01568 </u>
Firstly, Mean of above data,
=
=
= 1.188
Point estimate of Population Variance = Sample variance
=
=
= 3.92 *
.
Therefore, point estimate for the population variance = 3.92 *
.