Finding the Fourth Proportional to 78.78, 118.19 and 42.22

Step by Step Solution

1. Step 1: Write the proportion equation
   78.78 : 118.19 = 42.22 : x
2. Step 2: Convert to fraction form
   78.78/118.19 = 42.22/x
3. Step 3: Cross multiply
   78.78x = 118.19 × 42.22
4. Step 4: Simplify right side
   78.78x = 4,989.98
5. Step 5: Solve for x
   x = 4,989.98/78.78
6. Step 6: Final answer
   x = 63.34