Finding the Fourth Proportional to 1,291.52, 1,781.72 and 871.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,291.52 : 1,781.72 = 871.74 : x
2. Step 2: Convert to fraction form
   1,291.52/1,781.72 = 871.74/x
3. Step 3: Cross multiply
   1,291.52x = 1,781.72 × 871.74
4. Step 4: Simplify right side
   1,291.52x = 1,553,196.59
5. Step 5: Solve for x
   x = 1,553,196.59/1,291.52
6. Step 6: Final answer
   x = 1,202.61