Finding the Fourth Proportional to 17,720.11, 26,584.72 and 5,239.63

Step by Step Solution

1. Step 1: Write the proportion equation
   17,720.11 : 26,584.72 = 5,239.63 : x
2. Step 2: Convert to fraction form
   17,720.11/26,584.72 = 5,239.63/x
3. Step 3: Cross multiply
   17,720.11x = 26,584.72 × 5,239.63
4. Step 4: Simplify right side
   17,720.11x = 139,294,016.89
5. Step 5: Solve for x
   x = 139,294,016.89/17,720.11
6. Step 6: Final answer
   x = 7,860.79