Finding the Fourth Proportional to 82.38, 123.73 and 78.18

Step by Step Solution

1. Step 1: Write the proportion equation
   82.38 : 123.73 = 78.18 : x
2. Step 2: Convert to fraction form
   82.38/123.73 = 78.18/x
3. Step 3: Cross multiply
   82.38x = 123.73 × 78.18
4. Step 4: Simplify right side
   82.38x = 9,673.21
5. Step 5: Solve for x
   x = 9,673.21/82.38
6. Step 6: Final answer
   x = 117.42