Finding the Fourth Proportional to 100.94, 139.34 and 91.06

Step by Step Solution

1. Step 1: Write the proportion equation
   100.94 : 139.34 = 91.06 : x
2. Step 2: Convert to fraction form
   100.94/139.34 = 91.06/x
3. Step 3: Cross multiply
   100.94x = 139.34 × 91.06
4. Step 4: Simplify right side
   100.94x = 12,688.30
5. Step 5: Solve for x
   x = 12,688.30/100.94
6. Step 6: Final answer
   x = 125.70