Finding the Fourth Proportional to 2,086.48, 3,129.86 and 625.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.48 : 3,129.86 = 625.78 : x
2. Step 2: Convert to fraction form
   2,086.48/3,129.86 = 625.78/x
3. Step 3: Cross multiply
   2,086.48x = 3,129.86 × 625.78
4. Step 4: Simplify right side
   2,086.48x = 1,958,603.79
5. Step 5: Solve for x
   x = 1,958,603.79/2,086.48
6. Step 6: Final answer
   x = 938.71