Finding the Fourth Proportional to 82.96, 123.62 and 78.16

Step by Step Solution

1. Step 1: Write the proportion equation
   82.96 : 123.62 = 78.16 : x
2. Step 2: Convert to fraction form
   82.96/123.62 = 78.16/x
3. Step 3: Cross multiply
   82.96x = 123.62 × 78.16
4. Step 4: Simplify right side
   82.96x = 9,662.14
5. Step 5: Solve for x
   x = 9,662.14/82.96
6. Step 6: Final answer
   x = 116.47