Answer:
10π
Step-by-step explanation:
RULE: The angle measure of the central angle is congruent to the measure of the intercepted arc.
RULE: Central Angle = Arc length
Given:
Arc length (20 π) = central angle (180)
we know 180 degrees is a straight line, thus a semi-circle is created. This would be the diameter.
1/2 diameter is the radius. 20π/2 is the radius.
10π
Answer:

Step-by-step explanation:
Given

Let p represents the proportion of those who worry about identity theft;

Required
Mean of those who do not worry about identity theft
First, the proportion of those who do not worry, has to be calculated;
Represent this with q
In probability;

Make q the subject of formula

Substitute 

Convert percentage to fraction


Now, the mean can be calculated using:

Where n represents the population


(Approximated)
Your answer is 77/60 or 1 17/60