Finding the Fourth Proportional to 9,107.69, 12,568.46 and 5,128.79

Step by Step Solution

1. Step 1: Write the proportion equation
   9,107.69 : 12,568.46 = 5,128.79 : x
2. Step 2: Convert to fraction form
   9,107.69/12,568.46 = 5,128.79/x
3. Step 3: Cross multiply
   9,107.69x = 12,568.46 × 5,128.79
4. Step 4: Simplify right side
   9,107.69x = 64,460,903.48
5. Step 5: Solve for x
   x = 64,460,903.48/9,107.69
6. Step 6: Final answer
   x = 7,077.64