Finding the Fourth Proportional to 12,629.37, 17,421.42 and 7,905.45

Step by Step Solution

1. Step 1: Write the proportion equation
   12,629.37 : 17,421.42 = 7,905.45 : x
2. Step 2: Convert to fraction form
   12,629.37/17,421.42 = 7,905.45/x
3. Step 3: Cross multiply
   12,629.37x = 17,421.42 × 7,905.45
4. Step 4: Simplify right side
   12,629.37x = 137,724,164.74
5. Step 5: Solve for x
   x = 137,724,164.74/12,629.37
6. Step 6: Final answer
   x = 10,905.07