Finding the Fourth Proportional to 12,986.45, 17,921.30 and 7,018.12

Step by Step Solution

1. Step 1: Write the proportion equation
   12,986.45 : 17,921.30 = 7,018.12 : x
2. Step 2: Convert to fraction form
   12,986.45/17,921.30 = 7,018.12/x
3. Step 3: Cross multiply
   12,986.45x = 17,921.30 × 7,018.12
4. Step 4: Simplify right side
   12,986.45x = 125,773,833.96
5. Step 5: Solve for x
   x = 125,773,833.96/12,986.45
6. Step 6: Final answer
   x = 9,685.01