Finding the Fourth Proportional to 1,528.76, 2,109.57 and 865.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,528.76 : 2,109.57 = 865.59 : x
2. Step 2: Convert to fraction form
   1,528.76/2,109.57 = 865.59/x
3. Step 3: Cross multiply
   1,528.76x = 2,109.57 × 865.59
4. Step 4: Simplify right side
   1,528.76x = 1,826,022.70
5. Step 5: Solve for x
   x = 1,826,022.70/1,528.76
6. Step 6: Final answer
   x = 1,194.45