Finding the Fourth Proportional to 127.64, 191.42 and 42.12

Step by Step Solution

1. Step 1: Write the proportion equation
   127.64 : 191.42 = 42.12 : x
2. Step 2: Convert to fraction form
   127.64/191.42 = 42.12/x
3. Step 3: Cross multiply
   127.64x = 191.42 × 42.12
4. Step 4: Simplify right side
   127.64x = 8,062.61
5. Step 5: Solve for x
   x = 8,062.61/127.64
6. Step 6: Final answer
   x = 63.17