Finding the Fourth Proportional to 31,777, 47,678.72 and 13,998.56

Step by Step Solution

1. Step 1: Write the proportion equation
   31,777 : 47,678.72 = 13,998.56 : x
2. Step 2: Convert to fraction form
   31,777/47,678.72 = 13,998.56/x
3. Step 3: Cross multiply
   31,777x = 47,678.72 × 13,998.56
4. Step 4: Simplify right side
   31,777x = 667,433,422.64
5. Step 5: Solve for x
   x = 667,433,422.64/31,777
6. Step 6: Final answer
   x = 21,003.66