Finding the Fourth Proportional to 67.78, 101.50 and 51.55

Step by Step Solution

1. Step 1: Write the proportion equation
   67.78 : 101.50 = 51.55 : x
2. Step 2: Convert to fraction form
   67.78/101.50 = 51.55/x
3. Step 3: Cross multiply
   67.78x = 101.50 × 51.55
4. Step 4: Simplify right side
   67.78x = 5,231.94
5. Step 5: Solve for x
   x = 5,231.94/67.78
6. Step 6: Final answer
   x = 77.19