Finding the Fourth Proportional to 42.16, 63.12 and 21.82

Step by Step Solution

1. Step 1: Write the proportion equation
   42.16 : 63.12 = 21.82 : x
2. Step 2: Convert to fraction form
   42.16/63.12 = 21.82/x
3. Step 3: Cross multiply
   42.16x = 63.12 × 21.82
4. Step 4: Simplify right side
   42.16x = 1,377.28
5. Step 5: Solve for x
   x = 1,377.28/42.16
6. Step 6: Final answer
   x = 32.67