Finding the Fourth Proportional to 92.72, 139.83 and 91.69

Step by Step Solution

1. Step 1: Write the proportion equation
   92.72 : 139.83 = 91.69 : x
2. Step 2: Convert to fraction form
   92.72/139.83 = 91.69/x
3. Step 3: Cross multiply
   92.72x = 139.83 × 91.69
4. Step 4: Simplify right side
   92.72x = 12,821.01
5. Step 5: Solve for x
   x = 12,821.01/92.72
6. Step 6: Final answer
   x = 138.28