Finding the Fourth Proportional to 82.82, 123.50 and 78.76

Step by Step Solution

1. Step 1: Write the proportion equation
   82.82 : 123.50 = 78.76 : x
2. Step 2: Convert to fraction form
   82.82/123.50 = 78.76/x
3. Step 3: Cross multiply
   82.82x = 123.50 × 78.76
4. Step 4: Simplify right side
   82.82x = 9,726.86
5. Step 5: Solve for x
   x = 9,726.86/82.82
6. Step 6: Final answer
   x = 117.45