Finding the Fourth Proportional to 1,539.78, 2,124.77 and 876.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,539.78 : 2,124.77 = 876.50 : x
2. Step 2: Convert to fraction form
   1,539.78/2,124.77 = 876.50/x
3. Step 3: Cross multiply
   1,539.78x = 2,124.77 × 876.50
4. Step 4: Simplify right side
   1,539.78x = 1,862,355.29
5. Step 5: Solve for x
   x = 1,862,355.29/1,539.78
6. Step 6: Final answer
   x = 1,209.50