Finding the Fourth Proportional to 12,429.13, 17,145.74 and 7,705.21

Step by Step Solution

1. Step 1: Write the proportion equation
   12,429.13 : 17,145.74 = 7,705.21 : x
2. Step 2: Convert to fraction form
   12,429.13/17,145.74 = 7,705.21/x
3. Step 3: Cross multiply
   12,429.13x = 17,145.74 × 7,705.21
4. Step 4: Simplify right side
   12,429.13x = 132,111,527.31
5. Step 5: Solve for x
   x = 132,111,527.31/12,429.13
6. Step 6: Final answer
   x = 10,629.19