Finding the Fourth Proportional to 82.88, 124.30 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   82.88 : 124.30 = 42.18 : x
2. Step 2: Convert to fraction form
   82.88/124.30 = 42.18/x
3. Step 3: Cross multiply
   82.88x = 124.30 × 42.18
4. Step 4: Simplify right side
   82.88x = 5,242.97
5. Step 5: Solve for x
   x = 5,242.97/82.88
6. Step 6: Final answer
   x = 63.26