Finding the Fourth Proportional to 171,390.72, 256,638.72 and 137,928

Step by Step Solution

1. Step 1: Write the proportion equation
   171,390.72 : 256,638.72 = 137,928 : x
2. Step 2: Convert to fraction form
   171,390.72/256,638.72 = 137,928/x
3. Step 3: Cross multiply
   171,390.72x = 256,638.72 × 137,928
4. Step 4: Simplify right side
   171,390.72x = 35,397,665,372.16
5. Step 5: Solve for x
   x = 35,397,665,372.16/171,390.72
6. Step 6: Final answer
   x = 206,531.98