Finding the Fourth Proportional to 67.50, 100.78 and 57.36

Step by Step Solution

1. Step 1: Write the proportion equation
   67.50 : 100.78 = 57.36 : x
2. Step 2: Convert to fraction form
   67.50/100.78 = 57.36/x
3. Step 3: Cross multiply
   67.50x = 100.78 × 57.36
4. Step 4: Simplify right side
   67.50x = 5,780.74
5. Step 5: Solve for x
   x = 5,780.74/67.50
6. Step 6: Final answer
   x = 85.64