Finding the Fourth Proportional to 9,920.34, 13,690.08 and 5,728.86

Step by Step Solution

1. Step 1: Write the proportion equation
   9,920.34 : 13,690.08 = 5,728.86 : x
2. Step 2: Convert to fraction form
   9,920.34/13,690.08 = 5,728.86/x
3. Step 3: Cross multiply
   9,920.34x = 13,690.08 × 5,728.86
4. Step 4: Simplify right side
   9,920.34x = 78,428,551.71
5. Step 5: Solve for x
   x = 78,428,551.71/9,920.34
6. Step 6: Final answer
   x = 7,905.83