Finding the Fourth Proportional to 82.86, 124.28 and 42.31

Step by Step Solution

1. Step 1: Write the proportion equation
   82.86 : 124.28 = 42.31 : x
2. Step 2: Convert to fraction form
   82.86/124.28 = 42.31/x
3. Step 3: Cross multiply
   82.86x = 124.28 × 42.31
4. Step 4: Simplify right side
   82.86x = 5,257.93
5. Step 5: Solve for x
   x = 5,257.93/82.86
6. Step 6: Final answer
   x = 63.46