Finding the Fourth Proportional to 1,200.86, 1,656.15 and 781.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,200.86 : 1,656.15 = 781.06 : x
2. Step 2: Convert to fraction form
   1,200.86/1,656.15 = 781.06/x
3. Step 3: Cross multiply
   1,200.86x = 1,656.15 × 781.06
4. Step 4: Simplify right side
   1,200.86x = 1,293,551.85
5. Step 5: Solve for x
   x = 1,293,551.85/1,200.86
6. Step 6: Final answer
   x = 1,077.19