Finding the Fourth Proportional to 877.31, 1,314.42 and 781.98

Step by Step Solution

1. Step 1: Write the proportion equation
   877.31 : 1,314.42 = 781.98 : x
2. Step 2: Convert to fraction form
   877.31/1,314.42 = 781.98/x
3. Step 3: Cross multiply
   877.31x = 1,314.42 × 781.98
4. Step 4: Simplify right side
   877.31x = 1,027,850.15
5. Step 5: Solve for x
   x = 1,027,850.15/877.31
6. Step 6: Final answer
   x = 1,171.59