Finding the Fourth Proportional to 8,904.69, 12,289.39 and 5,128.00

Step by Step Solution

1. Step 1: Write the proportion equation
   8,904.69 : 12,289.39 = 5,128.00 : x
2. Step 2: Convert to fraction form
   8,904.69/12,289.39 = 5,128.00/x
3. Step 3: Cross multiply
   8,904.69x = 12,289.39 × 5,128.00
4. Step 4: Simplify right side
   8,904.69x = 63,019,948.38
5. Step 5: Solve for x
   x = 63,019,948.38/8,904.69
6. Step 6: Final answer
   x = 7,077.16