To solve this problem you must apply the proccedure shown below:
1. Clear the radius from the formula for the circumference of a circle and substitute values, as following:
![C=2\pi r\\ r=C/2\pi \\ r=37.699in/2\pi \\ r=5.99in](https://tex.z-dn.net/?f=%20C%3D2%5Cpi%20r%5C%5C%20r%3DC%2F2%5Cpi%20%5C%5C%20r%3D37.699in%2F2%5Cpi%20%5C%5C%20r%3D5.99in%20)
2. Substitute the radius calculated into the formula for calculate the surface area of the sphere:
![SA=4\pi r^{2} \\ SA=4\pi(5.99in^{2})\\ SA=450.88in^{2}](https://tex.z-dn.net/?f=%20SA%3D4%5Cpi%20r%5E%7B2%7D%20%5C%5C%20SA%3D4%5Cpi%285.99in%5E%7B2%7D%29%5C%5C%20SA%3D450.88in%5E%7B2%7D%20%20)
The answer is: ![450.88in^{2}](https://tex.z-dn.net/?f=%20450.88in%5E%7B2%7D%20%20)
Answer:
16:1
Step-by-step explanation:
The ratio of the surface areas of the similar solids is the square of the lengths.
(4:1)²
4²:1²
⇒ 16:1
Cost = fix cost + hourly cost - discount
Cost = 4* [5 + 4x - 4x(20/100)] = 4*[5 + 4x - 0.8x] = 4*[5 + 3.2x] = 20 + 12.8x
Answer: option B) 12.8x + 20