Finding the Fourth Proportional to 1,665.33, 2,498.16 and 787.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,665.33 : 2,498.16 = 787.80 : x
2. Step 2: Convert to fraction form
   1,665.33/2,498.16 = 787.80/x
3. Step 3: Cross multiply
   1,665.33x = 2,498.16 × 787.80
4. Step 4: Simplify right side
   1,665.33x = 1,968,050.45
5. Step 5: Solve for x
   x = 1,968,050.45/1,665.33
6. Step 6: Final answer
   x = 1,181.78