Finding the Fourth Proportional to 78.42, 108.24 and 50.78

Step by Step Solution

1. Step 1: Write the proportion equation
   78.42 : 108.24 = 50.78 : x
2. Step 2: Convert to fraction form
   78.42/108.24 = 50.78/x
3. Step 3: Cross multiply
   78.42x = 108.24 × 50.78
4. Step 4: Simplify right side
   78.42x = 5,496.94
5. Step 5: Solve for x
   x = 5,496.94/78.42
6. Step 6: Final answer
   x = 70.09