Finding the Fourth Proportional to 2,520.77, 3,781.58 and 878.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,520.77 : 3,781.58 = 878.31 : x
2. Step 2: Convert to fraction form
   2,520.77/3,781.58 = 878.31/x
3. Step 3: Cross multiply
   2,520.77x = 3,781.58 × 878.31
4. Step 4: Simplify right side
   2,520.77x = 3,321,395.14
5. Step 5: Solve for x
   x = 3,321,395.14/2,520.77
6. Step 6: Final answer
   x = 1,317.61