Finding the Fourth Proportional to 9,918.86, 13,687.94 and 5,729.42

Step by Step Solution

1. Step 1: Write the proportion equation
   9,918.86 : 13,687.94 = 5,729.42 : x
2. Step 2: Convert to fraction form
   9,918.86/13,687.94 = 5,729.42/x
3. Step 3: Cross multiply
   9,918.86x = 13,687.94 × 5,729.42
4. Step 4: Simplify right side
   9,918.86x = 78,423,957.19
5. Step 5: Solve for x
   x = 78,423,957.19/9,918.86
6. Step 6: Final answer
   x = 7,906.55