Finding the Fourth Proportional to 21,934.61, 30,267.90 and 12,980.53

Step by Step Solution

1. Step 1: Write the proportion equation
   21,934.61 : 30,267.90 = 12,980.53 : x
2. Step 2: Convert to fraction form
   21,934.61/30,267.90 = 12,980.53/x
3. Step 3: Cross multiply
   21,934.61x = 30,267.90 × 12,980.53
4. Step 4: Simplify right side
   21,934.61x = 392,893,308.32
5. Step 5: Solve for x
   x = 392,893,308.32/21,934.61
6. Step 6: Final answer
   x = 17,912.03