Finding the Fourth Proportional to 209,861.10, 314,864.55 and 91,617.30

Step by Step Solution

1. Step 1: Write the proportion equation
   209,861.10 : 314,864.55 = 91,617.30 : x
2. Step 2: Convert to fraction form
   209,861.10/314,864.55 = 91,617.30/x
3. Step 3: Cross multiply
   209,861.10x = 314,864.55 × 91,617.30
4. Step 4: Simplify right side
   209,861.10x = 28,847,039,936.72
5. Step 5: Solve for x
   x = 28,847,039,936.72/209,861.10
6. Step 6: Final answer
   x = 137,457.78