Finding the Fourth Proportional to 100.83, 139.22 and 86.93

Step by Step Solution

1. Step 1: Write the proportion equation
   100.83 : 139.22 = 86.93 : x
2. Step 2: Convert to fraction form
   100.83/139.22 = 86.93/x
3. Step 3: Cross multiply
   100.83x = 139.22 × 86.93
4. Step 4: Simplify right side
   100.83x = 12,101.26
5. Step 5: Solve for x
   x = 12,101.26/100.83
6. Step 6: Final answer
   x = 120.02