Finding the Fourth Proportional to 12,978.05, 17,909.71 and 7,009.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.05 : 17,909.71 = 7,009.72 : x
2. Step 2: Convert to fraction form
   12,978.05/17,909.71 = 7,009.72/x
3. Step 3: Cross multiply
   12,978.05x = 17,909.71 × 7,009.72
4. Step 4: Simplify right side
   12,978.05x = 125,542,052.38
5. Step 5: Solve for x
   x = 125,542,052.38/12,978.05
6. Step 6: Final answer
   x = 9,673.41