Finding the Fourth Proportional to 107.50, 148.20 and 72.50

Step by Step Solution

1. Step 1: Write the proportion equation
   107.50 : 148.20 = 72.50 : x
2. Step 2: Convert to fraction form
   107.50/148.20 = 72.50/x
3. Step 3: Cross multiply
   107.50x = 148.20 × 72.50
4. Step 4: Simplify right side
   107.50x = 10,744.50
5. Step 5: Solve for x
   x = 10,744.50/107.50
6. Step 6: Final answer
   x = 99.95