Finding the Fourth Proportional to 42.15, 63.17 and 34.55

Step by Step Solution

1. Step 1: Write the proportion equation
   42.15 : 63.17 = 34.55 : x
2. Step 2: Convert to fraction form
   42.15/63.17 = 34.55/x
3. Step 3: Cross multiply
   42.15x = 63.17 × 34.55
4. Step 4: Simplify right side
   42.15x = 2,182.64
5. Step 5: Solve for x
   x = 2,182.64/42.15
6. Step 6: Final answer
   x = 51.79