Finding the Fourth Proportional to 154.69, 213.50 and 99.50

Step by Step Solution

1. Step 1: Write the proportion equation
   154.69 : 213.50 = 99.50 : x
2. Step 2: Convert to fraction form
   154.69/213.50 = 99.50/x
3. Step 3: Cross multiply
   154.69x = 213.50 × 99.50
4. Step 4: Simplify right side
   154.69x = 21,241.69
5. Step 5: Solve for x
   x = 21,241.69/154.69
6. Step 6: Final answer
   x = 137.32