Finding the Fourth Proportional to 28,100.20, 42,116.82 and 13,087.12

Step by Step Solution

1. Step 1: Write the proportion equation
   28,100.20 : 42,116.82 = 13,087.12 : x
2. Step 2: Convert to fraction form
   28,100.20/42,116.82 = 13,087.12/x
3. Step 3: Cross multiply
   28,100.20x = 42,116.82 × 13,087.12
4. Step 4: Simplify right side
   28,100.20x = 551,187,877.36
5. Step 5: Solve for x
   x = 551,187,877.36/28,100.20
6. Step 6: Final answer
   x = 19,615.09