Finding the Fourth Proportional to 817,856.33, 1,226,978.55 and 256,890.83

Step by Step Solution

1. Step 1: Write the proportion equation
   817,856.33 : 1,226,978.55 = 256,890.83 : x
2. Step 2: Convert to fraction form
   817,856.33/1,226,978.55 = 256,890.83/x
3. Step 3: Cross multiply
   817,856.33x = 1,226,978.55 × 256,890.83
4. Step 4: Simplify right side
   817,856.33x = 315,199,531,966.80
5. Step 5: Solve for x
   x = 315,199,531,966.80/817,856.33
6. Step 6: Final answer
   x = 385,397.19