Finding the Fourth Proportional to 9,920.56, 13,690.36 and 5,671.71

Step by Step Solution

1. Step 1: Write the proportion equation
   9,920.56 : 13,690.36 = 5,671.71 : x
2. Step 2: Convert to fraction form
   9,920.56/13,690.36 = 5,671.71/x
3. Step 3: Cross multiply
   9,920.56x = 13,690.36 × 5,671.71
4. Step 4: Simplify right side
   9,920.56x = 77,647,751.72
5. Step 5: Solve for x
   x = 77,647,751.72/9,920.56
6. Step 6: Final answer
   x = 7,826.95