Finding the Fourth Proportional to 139.98, 209.74 and 99.34

Step by Step Solution

1. Step 1: Write the proportion equation
   139.98 : 209.74 = 99.34 : x
2. Step 2: Convert to fraction form
   139.98/209.74 = 99.34/x
3. Step 3: Cross multiply
   139.98x = 209.74 × 99.34
4. Step 4: Simplify right side
   139.98x = 20,835.57
5. Step 5: Solve for x
   x = 20,835.57/139.98
6. Step 6: Final answer
   x = 148.85