Finding the Fourth Proportional to 139.59, 208.53 and 98.69

Step by Step Solution

1. Step 1: Write the proportion equation
   139.59 : 208.53 = 98.69 : x
2. Step 2: Convert to fraction form
   139.59/208.53 = 98.69/x
3. Step 3: Cross multiply
   139.59x = 208.53 × 98.69
4. Step 4: Simplify right side
   139.59x = 20,578.78
5. Step 5: Solve for x
   x = 20,578.78/139.59
6. Step 6: Final answer
   x = 147.42