Finding the Fourth Proportional to 12,621.96, 17,406.50 and 9,975.69

Step by Step Solution

1. Step 1: Write the proportion equation
   12,621.96 : 17,406.50 = 9,975.69 : x
2. Step 2: Convert to fraction form
   12,621.96/17,406.50 = 9,975.69/x
3. Step 3: Cross multiply
   12,621.96x = 17,406.50 × 9,975.69
4. Step 4: Simplify right side
   12,621.96x = 173,641,798.11
5. Step 5: Solve for x
   x = 173,641,798.11/12,621.96
6. Step 6: Final answer
   x = 13,757.12