Finding the Fourth Proportional to 1,371.61, 1,892.48 and 811.85

Step by Step Solution

1. Step 1: Write the proportion equation
   1,371.61 : 1,892.48 = 811.85 : x
2. Step 2: Convert to fraction form
   1,371.61/1,892.48 = 811.85/x
3. Step 3: Cross multiply
   1,371.61x = 1,892.48 × 811.85
4. Step 4: Simplify right side
   1,371.61x = 1,536,409.89
5. Step 5: Solve for x
   x = 1,536,409.89/1,371.61
6. Step 6: Final answer
   x = 1,120.15