Finding the Fourth Proportional to 20,453.08, 30,676.56 and 7,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   20,453.08 : 30,676.56 = 7,978.72 : x
2. Step 2: Convert to fraction form
   20,453.08/30,676.56 = 7,978.72/x
3. Step 3: Cross multiply
   20,453.08x = 30,676.56 × 7,978.72
4. Step 4: Simplify right side
   20,453.08x = 244,759,682.80
5. Step 5: Solve for x
   x = 244,759,682.80/20,453.08
6. Step 6: Final answer
   x = 11,966.89