Finding the Fourth Proportional to 20,506.22, 30,719.37 and 12,986.72

Step by Step Solution

1. Step 1: Write the proportion equation
   20,506.22 : 30,719.37 = 12,986.72 : x
2. Step 2: Convert to fraction form
   20,506.22/30,719.37 = 12,986.72/x
3. Step 3: Cross multiply
   20,506.22x = 30,719.37 × 12,986.72
4. Step 4: Simplify right side
   20,506.22x = 398,943,856.77
5. Step 5: Solve for x
   x = 398,943,856.77/20,506.22
6. Step 6: Final answer
   x = 19,454.77