Finding the Fourth Proportional to 6,805.20, 9,390.86 and 3,972.72

Step by Step Solution

1. Step 1: Write the proportion equation
   6,805.20 : 9,390.86 = 3,972.72 : x
2. Step 2: Convert to fraction form
   6,805.20/9,390.86 = 3,972.72/x
3. Step 3: Cross multiply
   6,805.20x = 9,390.86 × 3,972.72
4. Step 4: Simplify right side
   6,805.20x = 37,307,257.34
5. Step 5: Solve for x
   x = 37,307,257.34/6,805.20
6. Step 6: Final answer
   x = 5,482.17