Finding the Fourth Proportional to 869,244,978.78, 1,199,870,091.17 and 516,820,128.74

Step by Step Solution

1. Step 1: Write the proportion equation
   869,244,978.78 : 1,199,870,091.17 = 516,820,128.74 : x
2. Step 2: Convert to fraction form
   869,244,978.78/1,199,870,091.17 = 516,820,128.74/x
3. Step 3: Cross multiply
   869,244,978.78x = 1,199,870,091.17 × 516,820,128.74
4. Step 4: Simplify right side
   869,244,978.78x = 620,117,014,989,755,008
5. Step 5: Solve for x
   x = 620,117,014,989,755,008/869,244,978.78
6. Step 6: Final answer
   x = 713,397,293.20