Finding the Fourth Proportional to 20,978.51, 31,472.37 and 9,134.17

Step by Step Solution

1. Step 1: Write the proportion equation
   20,978.51 : 31,472.37 = 9,134.17 : x
2. Step 2: Convert to fraction form
   20,978.51/31,472.37 = 9,134.17/x
3. Step 3: Cross multiply
   20,978.51x = 31,472.37 × 9,134.17
4. Step 4: Simplify right side
   20,978.51x = 287,473,899.20
5. Step 5: Solve for x
   x = 287,473,899.20/20,978.51
6. Step 6: Final answer
   x = 13,703.26