Finding the Fourth Proportional to 69.31, 103.85 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   69.31 : 103.85 = 42.18 : x
2. Step 2: Convert to fraction form
   69.31/103.85 = 42.18/x
3. Step 3: Cross multiply
   69.31x = 103.85 × 42.18
4. Step 4: Simplify right side
   69.31x = 4,380.39
5. Step 5: Solve for x
   x = 4,380.39/69.31
6. Step 6: Final answer
   x = 63.20