Finding the Fourth Proportional to 47,257.78, 70,900.53 and 13,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   47,257.78 : 70,900.53 = 13,978.72 : x
2. Step 2: Convert to fraction form
   47,257.78/70,900.53 = 13,978.72/x
3. Step 3: Cross multiply
   47,257.78x = 70,900.53 × 13,978.72
4. Step 4: Simplify right side
   47,257.78x = 991,098,656.72
5. Step 5: Solve for x
   x = 991,098,656.72/47,257.78
6. Step 6: Final answer
   x = 20,972.18