Finding the Fourth Proportional to 9,919.56, 13,686.85 and 5,725.38

Step by Step Solution

1. Step 1: Write the proportion equation
   9,919.56 : 13,686.85 = 5,725.38 : x
2. Step 2: Convert to fraction form
   9,919.56/13,686.85 = 5,725.38/x
3. Step 3: Cross multiply
   9,919.56x = 13,686.85 × 5,725.38
4. Step 4: Simplify right side
   9,919.56x = 78,362,417.25
5. Step 5: Solve for x
   x = 78,362,417.25/9,919.56
6. Step 6: Final answer
   x = 7,899.79