Finding the Fourth Proportional to 10,505.39, 15,719.15 and 8,419.07

Step by Step Solution

1. Step 1: Write the proportion equation
   10,505.39 : 15,719.15 = 8,419.07 : x
2. Step 2: Convert to fraction form
   10,505.39/15,719.15 = 8,419.07/x
3. Step 3: Cross multiply
   10,505.39x = 15,719.15 × 8,419.07
4. Step 4: Simplify right side
   10,505.39x = 132,340,684.54
5. Step 5: Solve for x
   x = 132,340,684.54/10,505.39
6. Step 6: Final answer
   x = 12,597.41