Finding the Fourth Proportional to 12,909.81, 19,379.31 and 5,124.09

Step by Step Solution

1. Step 1: Write the proportion equation
   12,909.81 : 19,379.31 = 5,124.09 : x
2. Step 2: Convert to fraction form
   12,909.81/19,379.31 = 5,124.09/x
3. Step 3: Cross multiply
   12,909.81x = 19,379.31 × 5,124.09
4. Step 4: Simplify right side
   12,909.81x = 99,301,328.58
5. Step 5: Solve for x
   x = 99,301,328.58/12,909.81
6. Step 6: Final answer
   x = 7,691.93