Finding the Fourth Proportional to 139.55, 209.33 and 42.05

Step by Step Solution

1. Step 1: Write the proportion equation
   139.55 : 209.33 = 42.05 : x
2. Step 2: Convert to fraction form
   139.55/209.33 = 42.05/x
3. Step 3: Cross multiply
   139.55x = 209.33 × 42.05
4. Step 4: Simplify right side
   139.55x = 8,802.64
5. Step 5: Solve for x
   x = 8,802.64/139.55
6. Step 6: Final answer
   x = 63.08