Finding the Fourth Proportional to 1,528.72, 2,109.46 and 856.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,528.72 : 2,109.46 = 856.55 : x
2. Step 2: Convert to fraction form
   1,528.72/2,109.46 = 856.55/x
3. Step 3: Cross multiply
   1,528.72x = 2,109.46 × 856.55
4. Step 4: Simplify right side
   1,528.72x = 1,806,857.96
5. Step 5: Solve for x
   x = 1,806,857.96/1,528.72
6. Step 6: Final answer
   x = 1,181.94