Finding the Fourth Proportional to 1,665.91, 2,498.35 and 787.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,665.91 : 2,498.35 = 787.91 : x
2. Step 2: Convert to fraction form
   1,665.91/2,498.35 = 787.91/x
3. Step 3: Cross multiply
   1,665.91x = 2,498.35 × 787.91
4. Step 4: Simplify right side
   1,665.91x = 1,968,474.95
5. Step 5: Solve for x
   x = 1,968,474.95/1,665.91
6. Step 6: Final answer
   x = 1,181.62