Finding the Fourth Proportional to 31,003.58, 42,785.07 and 18,428.42

Step by Step Solution

1. Step 1: Write the proportion equation
   31,003.58 : 42,785.07 = 18,428.42 : x
2. Step 2: Convert to fraction form
   31,003.58/42,785.07 = 18,428.42/x
3. Step 3: Cross multiply
   31,003.58x = 42,785.07 × 18,428.42
4. Step 4: Simplify right side
   31,003.58x = 788,461,239.69
5. Step 5: Solve for x
   x = 788,461,239.69/31,003.58
6. Step 6: Final answer
   x = 25,431.30