Finding the Fourth Proportional to 1,042.50, 1,438.61 and 570.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,042.50 : 1,438.61 = 570.39 : x
2. Step 2: Convert to fraction form
   1,042.50/1,438.61 = 570.39/x
3. Step 3: Cross multiply
   1,042.50x = 1,438.61 × 570.39
4. Step 4: Simplify right side
   1,042.50x = 820,571.81
5. Step 5: Solve for x
   x = 820,571.81/1,042.50
6. Step 6: Final answer
   x = 787.12