Finding the Fourth Proportional to 21,653.15, 29,881.71 and 12,700.89

Step by Step Solution

1. Step 1: Write the proportion equation
   21,653.15 : 29,881.71 = 12,700.89 : x
2. Step 2: Convert to fraction form
   21,653.15/29,881.71 = 12,700.89/x
3. Step 3: Cross multiply
   21,653.15x = 29,881.71 × 12,700.89
4. Step 4: Simplify right side
   21,653.15x = 379,524,311.72
5. Step 5: Solve for x
   x = 379,524,311.72/21,653.15
6. Step 6: Final answer
   x = 17,527.45