Finding the Fourth Proportional to 21,019,061,311.76, 28,851,796,296.42 and 18,586,910,159.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,019,061,311.76 : 28,851,796,296.42 = 18,586,910,159.12 : x
2. Step 2: Convert to fraction form
   21,019,061,311.76/28,851,796,296.42 = 18,586,910,159.12/x
3. Step 3: Cross multiply
   21,019,061,311.76x = 28,851,796,296.42 × 18,586,910,159.12
4. Step 4: Simplify right side
   21,019,061,311.76x = 536,265,745,690,789,609,472
5. Step 5: Solve for x
   x = 536,265,745,690,789,609,472/21,019,061,311.76
6. Step 6: Final answer
   x = 25,513,306,124.23