Finding the Fourth Proportional to 82.14, 123.34 and 78.63

Step by Step Solution

1. Step 1: Write the proportion equation
   82.14 : 123.34 = 78.63 : x
2. Step 2: Convert to fraction form
   82.14/123.34 = 78.63/x
3. Step 3: Cross multiply
   82.14x = 123.34 × 78.63
4. Step 4: Simplify right side
   82.14x = 9,697.71
5. Step 5: Solve for x
   x = 9,697.71/82.14
6. Step 6: Final answer
   x = 118.07