Finding the Fourth Proportional to 83.21, 124.72 and 42.58

Step by Step Solution

1. Step 1: Write the proportion equation
   83.21 : 124.72 = 42.58 : x
2. Step 2: Convert to fraction form
   83.21/124.72 = 42.58/x
3. Step 3: Cross multiply
   83.21x = 124.72 × 42.58
4. Step 4: Simplify right side
   83.21x = 5,310.58
5. Step 5: Solve for x
   x = 5,310.58/83.21
6. Step 6: Final answer
   x = 63.82