Finding the Third Proportional to 90,768 and 139,980

Step by Step Solution

1. Step 1: Write the proportion equation
   90,768 : 139,980 = 139,980 : x
2. Step 2: Convert to fraction form
   90,768/139,980 = 139,980/x
3. Step 3: Cross multiply
   90,768x = 139,980 × 139,980
4. Step 4: Simplify right side
   90,768x = 19,594,400,400
5. Step 5: Solve for x
   x = 19,594,400,400/90,768
6. Step 6: Final answer
   x = 215,873.44