Finding the Fourth Proportional to 78.89, 108.88 and 49.79

Step by Step Solution

1. Step 1: Write the proportion equation
   78.89 : 108.88 = 49.79 : x
2. Step 2: Convert to fraction form
   78.89/108.88 = 49.79/x
3. Step 3: Cross multiply
   78.89x = 108.88 × 49.79
4. Step 4: Simplify right side
   78.89x = 5,421.28
5. Step 5: Solve for x
   x = 5,421.28/78.89
6. Step 6: Final answer
   x = 68.72