Finding the Fourth Proportional to 13,105.79, 18,085.37 and 7,439.79

Step by Step Solution

1. Step 1: Write the proportion equation
   13,105.79 : 18,085.37 = 7,439.79 : x
2. Step 2: Convert to fraction form
   13,105.79/18,085.37 = 7,439.79/x
3. Step 3: Cross multiply
   13,105.79x = 18,085.37 × 7,439.79
4. Step 4: Simplify right side
   13,105.79x = 134,551,317.67
5. Step 5: Solve for x
   x = 134,551,317.67/13,105.79
6. Step 6: Final answer
   x = 10,266.56