Finding the Fourth Proportional to 1,345.28, 1,856.49 and 813.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.28 : 1,856.49 = 813.98 : x
2. Step 2: Convert to fraction form
   1,345.28/1,856.49 = 813.98/x
3. Step 3: Cross multiply
   1,345.28x = 1,856.49 × 813.98
4. Step 4: Simplify right side
   1,345.28x = 1,511,150.37
5. Step 5: Solve for x
   x = 1,511,150.37/1,345.28
6. Step 6: Final answer
   x = 1,123.30