Finding the Fourth Proportional to 100.91, 139.62 and 88.00

Step by Step Solution

1. Step 1: Write the proportion equation
   100.91 : 139.62 = 88.00 : x
2. Step 2: Convert to fraction form
   100.91/139.62 = 88.00/x
3. Step 3: Cross multiply
   100.91x = 139.62 × 88.00
4. Step 4: Simplify right side
   100.91x = 12,287.33
5. Step 5: Solve for x
   x = 12,287.33/100.91
6. Step 6: Final answer
   x = 121.76