Finding the Fourth Proportional to 100.98, 139.41 and 76.50

Step by Step Solution

1. Step 1: Write the proportion equation
   100.98 : 139.41 = 76.50 : x
2. Step 2: Convert to fraction form
   100.98/139.41 = 76.50/x
3. Step 3: Cross multiply
   100.98x = 139.41 × 76.50
4. Step 4: Simplify right side
   100.98x = 10,664.87
5. Step 5: Solve for x
   x = 10,664.87/100.98
6. Step 6: Final answer
   x = 105.61