Finding the Fourth Proportional to 83.21, 124.82 and 42.09

Step by Step Solution

1. Step 1: Write the proportion equation
   83.21 : 124.82 = 42.09 : x
2. Step 2: Convert to fraction form
   83.21/124.82 = 42.09/x
3. Step 3: Cross multiply
   83.21x = 124.82 × 42.09
4. Step 4: Simplify right side
   83.21x = 5,253.46
5. Step 5: Solve for x
   x = 5,253.46/83.21
6. Step 6: Final answer
   x = 63.14