Finding the Fourth Proportional to 109.55, 151.17 and 72.77

Step by Step Solution

1. Step 1: Write the proportion equation
   109.55 : 151.17 = 72.77 : x
2. Step 2: Convert to fraction form
   109.55/151.17 = 72.77/x
3. Step 3: Cross multiply
   109.55x = 151.17 × 72.77
4. Step 4: Simplify right side
   109.55x = 10,999.61
5. Step 5: Solve for x
   x = 10,999.61/109.55
6. Step 6: Final answer
   x = 100.40