Finding the Fourth Proportional to 100.85, 139.22 and 76.34

Step by Step Solution

1. Step 1: Write the proportion equation
   100.85 : 139.22 = 76.34 : x
2. Step 2: Convert to fraction form
   100.85/139.22 = 76.34/x
3. Step 3: Cross multiply
   100.85x = 139.22 × 76.34
4. Step 4: Simplify right side
   100.85x = 10,628.31
5. Step 5: Solve for x
   x = 10,628.31/100.85
6. Step 6: Final answer
   x = 105.39