Finding the Fourth Proportional to 82.37, 122.72 and 78.88

Step by Step Solution

1. Step 1: Write the proportion equation
   82.37 : 122.72 = 78.88 : x
2. Step 2: Convert to fraction form
   82.37/122.72 = 78.88/x
3. Step 3: Cross multiply
   82.37x = 122.72 × 78.88
4. Step 4: Simplify right side
   82.37x = 9,680.15
5. Step 5: Solve for x
   x = 9,680.15/82.37
6. Step 6: Final answer
   x = 117.52