Finding the Fourth Proportional to 83.21, 124.91 and 42.71

Step by Step Solution

1. Step 1: Write the proportion equation
   83.21 : 124.91 = 42.71 : x
2. Step 2: Convert to fraction form
   83.21/124.91 = 42.71/x
3. Step 3: Cross multiply
   83.21x = 124.91 × 42.71
4. Step 4: Simplify right side
   83.21x = 5,334.69
5. Step 5: Solve for x
   x = 5,334.69/83.21
6. Step 6: Final answer
   x = 64.11