Finding the Fourth Proportional to 18,976.72, 28,443.18 and 10,209.28

Step by Step Solution

1. Step 1: Write the proportion equation
   18,976.72 : 28,443.18 = 10,209.28 : x
2. Step 2: Convert to fraction form
   18,976.72/28,443.18 = 10,209.28/x
3. Step 3: Cross multiply
   18,976.72x = 28,443.18 × 10,209.28
4. Step 4: Simplify right side
   18,976.72x = 290,384,388.71
5. Step 5: Solve for x
   x = 290,384,388.71/18,976.72
6. Step 6: Final answer
   x = 15,302.14