Finding the Fourth Proportional to 9,405.65, 12,980.20 and 5,628.09

Step by Step Solution

1. Step 1: Write the proportion equation
   9,405.65 : 12,980.20 = 5,628.09 : x
2. Step 2: Convert to fraction form
   9,405.65/12,980.20 = 5,628.09/x
3. Step 3: Cross multiply
   9,405.65x = 12,980.20 × 5,628.09
4. Step 4: Simplify right side
   9,405.65x = 73,053,732.90
5. Step 5: Solve for x
   x = 73,053,732.90/9,405.65
6. Step 6: Final answer
   x = 7,767.01