Answer:
r=41/2
Step-by-step explanation:
You have to divide the diameter, 41, by 2 because the radius of the circle is half of the diameter. So, the answer would be 20.5
If the annual rate in 10 years has the same quadralaterical value the answer would be 47.9 but we can make sure our answer is correct
what we know:
The cost changed in 10 years to 23.95
if the cost changed another 10 years it would be another 23.95, 23.95+23.95=47.9 Which is our answer pls mark brainliest