Finding the Fourth Proportional to 1,345.44, 1,856.81 and 821.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.44 : 1,856.81 = 821.57 : x
2. Step 2: Convert to fraction form
   1,345.44/1,856.81 = 821.57/x
3. Step 3: Cross multiply
   1,345.44x = 1,856.81 × 821.57
4. Step 4: Simplify right side
   1,345.44x = 1,525,495.28
5. Step 5: Solve for x
   x = 1,525,495.28/1,345.44
6. Step 6: Final answer
   x = 1,133.83