Finding the Fourth Proportional to 78.32, 117.50 and 67.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78.32 : 117.50 = 67.72 : x
2. Step 2: Convert to fraction form
   78.32/117.50 = 67.72/x
3. Step 3: Cross multiply
   78.32x = 117.50 × 67.72
4. Step 4: Simplify right side
   78.32x = 7,957.10
5. Step 5: Solve for x
   x = 7,957.10/78.32
6. Step 6: Final answer
   x = 101.60