Finding the Fourth Proportional to 83.31, 124.92 and 42.72

Step by Step Solution

1. Step 1: Write the proportion equation
   83.31 : 124.92 = 42.72 : x
2. Step 2: Convert to fraction form
   83.31/124.92 = 42.72/x
3. Step 3: Cross multiply
   83.31x = 124.92 × 42.72
4. Step 4: Simplify right side
   83.31x = 5,336.58
5. Step 5: Solve for x
   x = 5,336.58/83.31
6. Step 6: Final answer
   x = 64.06