Finding the Fourth Proportional to 90.72, 125.15 and 80.46

Step by Step Solution

1. Step 1: Write the proportion equation
   90.72 : 125.15 = 80.46 : x
2. Step 2: Convert to fraction form
   90.72/125.15 = 80.46/x
3. Step 3: Cross multiply
   90.72x = 125.15 × 80.46
4. Step 4: Simplify right side
   90.72x = 10,069.17
5. Step 5: Solve for x
   x = 10,069.17/90.72
6. Step 6: Final answer
   x = 110.99