Finding the Fourth Proportional to 2,085.38, 3,128.91 and 787.22

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.38 : 3,128.91 = 787.22 : x
2. Step 2: Convert to fraction form
   2,085.38/3,128.91 = 787.22/x
3. Step 3: Cross multiply
   2,085.38x = 3,128.91 × 787.22
4. Step 4: Simplify right side
   2,085.38x = 2,463,140.53
5. Step 5: Solve for x
   x = 2,463,140.53/2,085.38
6. Step 6: Final answer
   x = 1,181.15