Finding the Fourth Proportional to 11,685.15, 17,438.30 and 10,438.56

Step by Step Solution

1. Step 1: Write the proportion equation
   11,685.15 : 17,438.30 = 10,438.56 : x
2. Step 2: Convert to fraction form
   11,685.15/17,438.30 = 10,438.56/x
3. Step 3: Cross multiply
   11,685.15x = 17,438.30 × 10,438.56
4. Step 4: Simplify right side
   11,685.15x = 182,030,688.66
5. Step 5: Solve for x
   x = 182,030,688.66/11,685.15
6. Step 6: Final answer
   x = 15,577.95