Finding the Fourth Proportional to 31,006.40, 42,795 and 18,428.72

Step by Step Solution

1. Step 1: Write the proportion equation
   31,006.40 : 42,795 = 18,428.72 : x
2. Step 2: Convert to fraction form
   31,006.40/42,795 = 18,428.72/x
3. Step 3: Cross multiply
   31,006.40x = 42,795 × 18,428.72
4. Step 4: Simplify right side
   31,006.40x = 788,657,072.40
5. Step 5: Solve for x
   x = 788,657,072.40/31,006.40
6. Step 6: Final answer
   x = 25,435.30