Finding the Third Proportional to 42,720 and 57,120

Step by Step Solution

1. Step 1: Write the proportion equation
   42,720 : 57,120 = 57,120 : x
2. Step 2: Convert to fraction form
   42,720/57,120 = 57,120/x
3. Step 3: Cross multiply
   42,720x = 57,120 × 57,120
4. Step 4: Simplify right side
   42,720x = 3,262,694,400
5. Step 5: Solve for x
   x = 3,262,694,400/42,720
6. Step 6: Final answer
   x = 76,373.93