Finding the Fourth Proportional to 82.18, 123.12 and 58.15

Step by Step Solution

1. Step 1: Write the proportion equation
   82.18 : 123.12 = 58.15 : x
2. Step 2: Convert to fraction form
   82.18/123.12 = 58.15/x
3. Step 3: Cross multiply
   82.18x = 123.12 × 58.15
4. Step 4: Simplify right side
   82.18x = 7,159.43
5. Step 5: Solve for x
   x = 7,159.43/82.18
6. Step 6: Final answer
   x = 87.12