Finding the Third Proportional to 85.78 and 123.05

Step by Step Solution

1. Step 1: Write the proportion equation
   85.78 : 123.05 = 123.05 : x
2. Step 2: Convert to fraction form
   85.78/123.05 = 123.05/x
3. Step 3: Cross multiply
   85.78x = 123.05 × 123.05
4. Step 4: Simplify right side
   85.78x = 15,140.53
5. Step 5: Solve for x
   x = 15,140.53/85.78
6. Step 6: Final answer
   x = 176.50