Finding the Fourth Proportional to 8,905.01, 12,288.54 and 5,128.31

Step by Step Solution

1. Step 1: Write the proportion equation
   8,905.01 : 12,288.54 = 5,128.31 : x
2. Step 2: Convert to fraction form
   8,905.01/12,288.54 = 5,128.31/x
3. Step 3: Cross multiply
   8,905.01x = 12,288.54 × 5,128.31
4. Step 4: Simplify right side
   8,905.01x = 63,019,492.52
5. Step 5: Solve for x
   x = 63,019,492.52/8,905.01
6. Step 6: Final answer
   x = 7,076.86