Finding the Fourth Proportional to 1,345.55, 1,856.84 and 821.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.55 : 1,856.84 = 821.58 : x
2. Step 2: Convert to fraction form
   1,345.55/1,856.84 = 821.58/x
3. Step 3: Cross multiply
   1,345.55x = 1,856.84 × 821.58
4. Step 4: Simplify right side
   1,345.55x = 1,525,531.54
5. Step 5: Solve for x
   x = 1,525,531.54/1,345.55
6. Step 6: Final answer
   x = 1,133.76