Finding the Fourth Proportional to 9,170.72, 12,655.16 and 4,978.88

Step by Step Solution

1. Step 1: Write the proportion equation
   9,170.72 : 12,655.16 = 4,978.88 : x
2. Step 2: Convert to fraction form
   9,170.72/12,655.16 = 4,978.88/x
3. Step 3: Cross multiply
   9,170.72x = 12,655.16 × 4,978.88
4. Step 4: Simplify right side
   9,170.72x = 63,008,523.02
5. Step 5: Solve for x
   x = 63,008,523.02/9,170.72
6. Step 6: Final answer
   x = 6,870.62