Finding the Fourth Proportional to 124.99, 172.50 and 72.55

Step by Step Solution

1. Step 1: Write the proportion equation
   124.99 : 172.50 = 72.55 : x
2. Step 2: Convert to fraction form
   124.99/172.50 = 72.55/x
3. Step 3: Cross multiply
   124.99x = 172.50 × 72.55
4. Step 4: Simplify right side
   124.99x = 12,514.69
5. Step 5: Solve for x
   x = 12,514.69/124.99
6. Step 6: Final answer
   x = 100.12