Finding the Fourth Proportional to 9,918.87, 13,685.90 and 5,724.69

Step by Step Solution

1. Step 1: Write the proportion equation
   9,918.87 : 13,685.90 = 5,724.69 : x
2. Step 2: Convert to fraction form
   9,918.87/13,685.90 = 5,724.69/x
3. Step 3: Cross multiply
   9,918.87x = 13,685.90 × 5,724.69
4. Step 4: Simplify right side
   9,918.87x = 78,347,486.34
5. Step 5: Solve for x
   x = 78,347,486.34/9,918.87
6. Step 6: Final answer
   x = 7,898.83