Finding the Fourth Proportional to 17,189.76, 25,789.52 and 8,427.20

Step by Step Solution

1. Step 1: Write the proportion equation
   17,189.76 : 25,789.52 = 8,427.20 : x
2. Step 2: Convert to fraction form
   17,189.76/25,789.52 = 8,427.20/x
3. Step 3: Cross multiply
   17,189.76x = 25,789.52 × 8,427.20
4. Step 4: Simplify right side
   17,189.76x = 217,333,442.94
5. Step 5: Solve for x
   x = 217,333,442.94/17,189.76
6. Step 6: Final answer
   x = 12,643.19