Finding the Third Proportional to 100.78 and 155.91

Step by Step Solution

1. Step 1: Write the proportion equation
   100.78 : 155.91 = 155.91 : x
2. Step 2: Convert to fraction form
   100.78/155.91 = 155.91/x
3. Step 3: Cross multiply
   100.78x = 155.91 × 155.91
4. Step 4: Simplify right side
   100.78x = 24,306.76
5. Step 5: Solve for x
   x = 24,306.76/100.78
6. Step 6: Final answer
   x = 241.18