Finding the Fourth Proportional to 2,978.86, 4,468.64 and 787.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,978.86 : 4,468.64 = 787.60 : x
2. Step 2: Convert to fraction form
   2,978.86/4,468.64 = 787.60/x
3. Step 3: Cross multiply
   2,978.86x = 4,468.64 × 787.60
4. Step 4: Simplify right side
   2,978.86x = 3,519,500.86
5. Step 5: Solve for x
   x = 3,519,500.86/2,978.86
6. Step 6: Final answer
   x = 1,181.49