Finding the Fourth Proportional to 42.76, 63.65 and 42.15

Step by Step Solution

1. Step 1: Write the proportion equation
   42.76 : 63.65 = 42.15 : x
2. Step 2: Convert to fraction form
   42.76/63.65 = 42.15/x
3. Step 3: Cross multiply
   42.76x = 63.65 × 42.15
4. Step 4: Simplify right side
   42.76x = 2,682.85
5. Step 5: Solve for x
   x = 2,682.85/42.76
6. Step 6: Final answer
   x = 62.74