Finding the Third Proportional to 78.31 and 121.06

Step by Step Solution

1. Step 1: Write the proportion equation
   78.31 : 121.06 = 121.06 : x
2. Step 2: Convert to fraction form
   78.31/121.06 = 121.06/x
3. Step 3: Cross multiply
   78.31x = 121.06 × 121.06
4. Step 4: Simplify right side
   78.31x = 14,656.13
5. Step 5: Solve for x
   x = 14,656.13/78.31
6. Step 6: Final answer
   x = 187.15