Finding the Fourth Proportional to 100.82, 139.31 and 74.55

Step by Step Solution

1. Step 1: Write the proportion equation
   100.82 : 139.31 = 74.55 : x
2. Step 2: Convert to fraction form
   100.82/139.31 = 74.55/x
3. Step 3: Cross multiply
   100.82x = 139.31 × 74.55
4. Step 4: Simplify right side
   100.82x = 10,385.19
5. Step 5: Solve for x
   x = 10,385.19/100.82
6. Step 6: Final answer
   x = 103.01