Finding the Fourth Proportional to 92.34, 139.27 and 91.31

Step by Step Solution

1. Step 1: Write the proportion equation
   92.34 : 139.27 = 91.31 : x
2. Step 2: Convert to fraction form
   92.34/139.27 = 91.31/x
3. Step 3: Cross multiply
   92.34x = 139.27 × 91.31
4. Step 4: Simplify right side
   92.34x = 12,716.77
5. Step 5: Solve for x
   x = 12,716.77/92.34
6. Step 6: Final answer
   x = 137.72