Finding the Fourth Proportional to 1,216.72, 1,677.92 and 843.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.72 : 1,677.92 = 843.76 : x
2. Step 2: Convert to fraction form
   1,216.72/1,677.92 = 843.76/x
3. Step 3: Cross multiply
   1,216.72x = 1,677.92 × 843.76
4. Step 4: Simplify right side
   1,216.72x = 1,415,761.78
5. Step 5: Solve for x
   x = 1,415,761.78/1,216.72
6. Step 6: Final answer
   x = 1,163.59