Finding the Fourth Proportional to 12,820.61, 17,700.45 and 9,830.70

Step by Step Solution

1. Step 1: Write the proportion equation
   12,820.61 : 17,700.45 = 9,830.70 : x
2. Step 2: Convert to fraction form
   12,820.61/17,700.45 = 9,830.70/x
3. Step 3: Cross multiply
   12,820.61x = 17,700.45 × 9,830.70
4. Step 4: Simplify right side
   12,820.61x = 174,007,813.82
5. Step 5: Solve for x
   x = 174,007,813.82/12,820.61
6. Step 6: Final answer
   x = 13,572.51