Finding the Third Proportional to 89.86 and 139.08

Step by Step Solution

1. Step 1: Write the proportion equation
   89.86 : 139.08 = 139.08 : x
2. Step 2: Convert to fraction form
   89.86/139.08 = 139.08/x
3. Step 3: Cross multiply
   89.86x = 139.08 × 139.08
4. Step 4: Simplify right side
   89.86x = 19,342.72
5. Step 5: Solve for x
   x = 19,342.72/89.86
6. Step 6: Final answer
   x = 215.26