Finding the Fourth Proportional to 74.86, 103.31 and 42.12

Step by Step Solution

1. Step 1: Write the proportion equation
   74.86 : 103.31 = 42.12 : x
2. Step 2: Convert to fraction form
   74.86/103.31 = 42.12/x
3. Step 3: Cross multiply
   74.86x = 103.31 × 42.12
4. Step 4: Simplify right side
   74.86x = 4,350.69
5. Step 5: Solve for x
   x = 4,350.69/74.86
6. Step 6: Final answer
   x = 58.12