Finding the Fourth Proportional to 100.50, 138.72 and 67.86

Step by Step Solution

1. Step 1: Write the proportion equation
   100.50 : 138.72 = 67.86 : x
2. Step 2: Convert to fraction form
   100.50/138.72 = 67.86/x
3. Step 3: Cross multiply
   100.50x = 138.72 × 67.86
4. Step 4: Simplify right side
   100.50x = 9,413.54
5. Step 5: Solve for x
   x = 9,413.54/100.50
6. Step 6: Final answer
   x = 93.67