Finding the Fourth Proportional to 20,697.70, 28,568.82 and 13,528.71

Step by Step Solution

1. Step 1: Write the proportion equation
   20,697.70 : 28,568.82 = 13,528.71 : x
2. Step 2: Convert to fraction form
   20,697.70/28,568.82 = 13,528.71/x
3. Step 3: Cross multiply
   20,697.70x = 28,568.82 × 13,528.71
4. Step 4: Simplify right side
   20,697.70x = 386,499,280.82
5. Step 5: Solve for x
   x = 386,499,280.82/20,697.70
6. Step 6: Final answer
   x = 18,673.54