Finding the Fourth Proportional to 1,153.98, 1,591.90 and 781.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,153.98 : 1,591.90 = 781.07 : x
2. Step 2: Convert to fraction form
   1,153.98/1,591.90 = 781.07/x
3. Step 3: Cross multiply
   1,153.98x = 1,591.90 × 781.07
4. Step 4: Simplify right side
   1,153.98x = 1,243,375.42
5. Step 5: Solve for x
   x = 1,243,375.42/1,153.98
6. Step 6: Final answer
   x = 1,077.47