Finding the Fourth Proportional to 31,005.97, 42,773.21 and 18,421.81

Step by Step Solution

1. Step 1: Write the proportion equation
   31,005.97 : 42,773.21 = 18,421.81 : x
2. Step 2: Convert to fraction form
   31,005.97/42,773.21 = 18,421.81/x
3. Step 3: Cross multiply
   31,005.97x = 42,773.21 × 18,421.81
4. Step 4: Simplify right side
   31,005.97x = 787,959,855.60
5. Step 5: Solve for x
   x = 787,959,855.60/31,005.97
6. Step 6: Final answer
   x = 25,413.17