Finding the Fourth Proportional to 19,931.36, 27,508.56 and 15,206.72

Step by Step Solution

1. Step 1: Write the proportion equation
   19,931.36 : 27,508.56 = 15,206.72 : x
2. Step 2: Convert to fraction form
   19,931.36/27,508.56 = 15,206.72/x
3. Step 3: Cross multiply
   19,931.36x = 27,508.56 × 15,206.72
4. Step 4: Simplify right side
   19,931.36x = 418,314,969.52
5. Step 5: Solve for x
   x = 418,314,969.52/19,931.36
6. Step 6: Final answer
   x = 20,987.78