Finding the Third Proportional to 31,439.25 and 42,720.75

Step by Step Solution

1. Step 1: Write the proportion equation
   31,439.25 : 42,720.75 = 42,720.75 : x
2. Step 2: Convert to fraction form
   31,439.25/42,720.75 = 42,720.75/x
3. Step 3: Cross multiply
   31,439.25x = 42,720.75 × 42,720.75
4. Step 4: Simplify right side
   31,439.25x = 1,825,062,480.56
5. Step 5: Solve for x
   x = 1,825,062,480.56/31,439.25
6. Step 6: Final answer
   x = 58,050.45