Finding the Fourth Proportional to 20,978.37, 31,430.63 and 19,729.73

Step by Step Solution

1. Step 1: Write the proportion equation
   20,978.37 : 31,430.63 = 19,729.73 : x
2. Step 2: Convert to fraction form
   20,978.37/31,430.63 = 19,729.73/x
3. Step 3: Cross multiply
   20,978.37x = 31,430.63 × 19,729.73
4. Step 4: Simplify right side
   20,978.37x = 620,117,843.63
5. Step 5: Solve for x
   x = 620,117,843.63/20,978.37
6. Step 6: Final answer
   x = 29,559.87