Finding the Fourth Proportional to 645,085.50, 890,240.83 and 354,719.16

Step by Step Solution

1. Step 1: Write the proportion equation
   645,085.50 : 890,240.83 = 354,719.16 : x
2. Step 2: Convert to fraction form
   645,085.50/890,240.83 = 354,719.16/x
3. Step 3: Cross multiply
   645,085.50x = 890,240.83 × 354,719.16
4. Step 4: Simplify right side
   645,085.50x = 315,785,478,528.51
5. Step 5: Solve for x
   x = 315,785,478,528.51/645,085.50
6. Step 6: Final answer
   x = 489,525.00