Finding the Fourth Proportional to 5,085.57, 7,628.29 and 1,387.72

Step by Step Solution

1. Step 1: Write the proportion equation
   5,085.57 : 7,628.29 = 1,387.72 : x
2. Step 2: Convert to fraction form
   5,085.57/7,628.29 = 1,387.72/x
3. Step 3: Cross multiply
   5,085.57x = 7,628.29 × 1,387.72
4. Step 4: Simplify right side
   5,085.57x = 10,585,930.60
5. Step 5: Solve for x
   x = 10,585,930.60/5,085.57
6. Step 6: Final answer
   x = 2,081.56