Finding the Fourth Proportional to 1,345.35, 1,856.57 and 821.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.35 : 1,856.57 = 821.38 : x
2. Step 2: Convert to fraction form
   1,345.35/1,856.57 = 821.38/x
3. Step 3: Cross multiply
   1,345.35x = 1,856.57 × 821.38
4. Step 4: Simplify right side
   1,345.35x = 1,524,940.18
5. Step 5: Solve for x
   x = 1,524,940.18/1,345.35
6. Step 6: Final answer
   x = 1,133.49