Finding the Fourth Proportional to 42.38, 63.55 and 15.31

Step by Step Solution

1. Step 1: Write the proportion equation
   42.38 : 63.55 = 15.31 : x
2. Step 2: Convert to fraction form
   42.38/63.55 = 15.31/x
3. Step 3: Cross multiply
   42.38x = 63.55 × 15.31
4. Step 4: Simplify right side
   42.38x = 972.95
5. Step 5: Solve for x
   x = 972.95/42.38
6. Step 6: Final answer
   x = 22.96