Finding the Fourth Proportional to 1,355.67, 1,872.37 and 912.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.67 : 1,872.37 = 912.81 : x
2. Step 2: Convert to fraction form
   1,355.67/1,872.37 = 912.81/x
3. Step 3: Cross multiply
   1,355.67x = 1,872.37 × 912.81
4. Step 4: Simplify right side
   1,355.67x = 1,709,118.06
5. Step 5: Solve for x
   x = 1,709,118.06/1,355.67
6. Step 6: Final answer
   x = 1,260.72