Finding the Fourth Proportional to 67.15, 100.83 and 53.74

Step by Step Solution

1. Step 1: Write the proportion equation
   67.15 : 100.83 = 53.74 : x
2. Step 2: Convert to fraction form
   67.15/100.83 = 53.74/x
3. Step 3: Cross multiply
   67.15x = 100.83 × 53.74
4. Step 4: Simplify right side
   67.15x = 5,418.60
5. Step 5: Solve for x
   x = 5,418.60/67.15
6. Step 6: Final answer
   x = 80.69