Finding the Fourth Proportional to 31,047.46, 42,846.44 and 21,989.05

Step by Step Solution

1. Step 1: Write the proportion equation
   31,047.46 : 42,846.44 = 21,989.05 : x
2. Step 2: Convert to fraction form
   31,047.46/42,846.44 = 21,989.05/x
3. Step 3: Cross multiply
   31,047.46x = 42,846.44 × 21,989.05
4. Step 4: Simplify right side
   31,047.46x = 942,152,511.48
5. Step 5: Solve for x
   x = 942,152,511.48/31,047.46
6. Step 6: Final answer
   x = 30,345.56