Finding the Fourth Proportional to 1,528.89, 2,109.92 and 856.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,528.89 : 2,109.92 = 856.72 : x
2. Step 2: Convert to fraction form
   1,528.89/2,109.92 = 856.72/x
3. Step 3: Cross multiply
   1,528.89x = 2,109.92 × 856.72
4. Step 4: Simplify right side
   1,528.89x = 1,807,609.34
5. Step 5: Solve for x
   x = 1,807,609.34/1,528.89
6. Step 6: Final answer
   x = 1,182.30