Finding the Fourth Proportional to 100.94, 139.61 and 90.01

Step by Step Solution

1. Step 1: Write the proportion equation
   100.94 : 139.61 = 90.01 : x
2. Step 2: Convert to fraction form
   100.94/139.61 = 90.01/x
3. Step 3: Cross multiply
   100.94x = 139.61 × 90.01
4. Step 4: Simplify right side
   100.94x = 12,565.15
5. Step 5: Solve for x
   x = 12,565.15/100.94
6. Step 6: Final answer
   x = 124.48