Finding the Fourth Proportional to 78.94, 108.80 and 67.31

Step by Step Solution

1. Step 1: Write the proportion equation
   78.94 : 108.80 = 67.31 : x
2. Step 2: Convert to fraction form
   78.94/108.80 = 67.31/x
3. Step 3: Cross multiply
   78.94x = 108.80 × 67.31
4. Step 4: Simplify right side
   78.94x = 7,323.33
5. Step 5: Solve for x
   x = 7,323.33/78.94
6. Step 6: Final answer
   x = 92.77