Finding the Fourth Proportional to 139.69, 209.50 and 58.53

Step by Step Solution

1. Step 1: Write the proportion equation
   139.69 : 209.50 = 58.53 : x
2. Step 2: Convert to fraction form
   139.69/209.50 = 58.53/x
3. Step 3: Cross multiply
   139.69x = 209.50 × 58.53
4. Step 4: Simplify right side
   139.69x = 12,261.74
5. Step 5: Solve for x
   x = 12,261.74/139.69
6. Step 6: Final answer
   x = 87.78