Finding the Fourth Proportional to 100.82, 139.15 and 63.50

Step by Step Solution

1. Step 1: Write the proportion equation
   100.82 : 139.15 = 63.50 : x
2. Step 2: Convert to fraction form
   100.82/139.15 = 63.50/x
3. Step 3: Cross multiply
   100.82x = 139.15 × 63.50
4. Step 4: Simplify right side
   100.82x = 8,836.03
5. Step 5: Solve for x
   x = 8,836.03/100.82
6. Step 6: Final answer
   x = 87.64