Finding the Fourth Proportional to 42.31, 63.42 and 18.25

Step by Step Solution

1. Step 1: Write the proportion equation
   42.31 : 63.42 = 18.25 : x
2. Step 2: Convert to fraction form
   42.31/63.42 = 18.25/x
3. Step 3: Cross multiply
   42.31x = 63.42 × 18.25
4. Step 4: Simplify right side
   42.31x = 1,157.42
5. Step 5: Solve for x
   x = 1,157.42/42.31
6. Step 6: Final answer
   x = 27.36