Finding the Fourth Proportional to 71.31, 107.16 and 42.42

Step by Step Solution

1. Step 1: Write the proportion equation
   71.31 : 107.16 = 42.42 : x
2. Step 2: Convert to fraction form
   71.31/107.16 = 42.42/x
3. Step 3: Cross multiply
   71.31x = 107.16 × 42.42
4. Step 4: Simplify right side
   71.31x = 4,546.00
5. Step 5: Solve for x
   x = 4,546.00/71.31
6. Step 6: Final answer
   x = 63.75