Finding the Fourth Proportional to 78.42, 117.27 and 67.71

Step by Step Solution

1. Step 1: Write the proportion equation
   78.42 : 117.27 = 67.71 : x
2. Step 2: Convert to fraction form
   78.42/117.27 = 67.71/x
3. Step 3: Cross multiply
   78.42x = 117.27 × 67.71
4. Step 4: Simplify right side
   78.42x = 7,940.65
5. Step 5: Solve for x
   x = 7,940.65/78.42
6. Step 6: Final answer
   x = 101.26