Finding the Fourth Proportional to 51.29, 76.89 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   51.29 : 76.89 = 42.18 : x
2. Step 2: Convert to fraction form
   51.29/76.89 = 42.18/x
3. Step 3: Cross multiply
   51.29x = 76.89 × 42.18
4. Step 4: Simplify right side
   51.29x = 3,243.32
5. Step 5: Solve for x
   x = 3,243.32/51.29
6. Step 6: Final answer
   x = 63.23