Finding the Fourth Proportional to 1,345.30, 1,856.60 and 821.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.30 : 1,856.60 = 821.34 : x
2. Step 2: Convert to fraction form
   1,345.30/1,856.60 = 821.34/x
3. Step 3: Cross multiply
   1,345.30x = 1,856.60 × 821.34
4. Step 4: Simplify right side
   1,345.30x = 1,524,899.84
5. Step 5: Solve for x
   x = 1,524,899.84/1,345.30
6. Step 6: Final answer
   x = 1,133.50