Finding the Fourth Proportional to 78.87, 108.93 and 72.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78.87 : 108.93 = 72.72 : x
2. Step 2: Convert to fraction form
   78.87/108.93 = 72.72/x
3. Step 3: Cross multiply
   78.87x = 108.93 × 72.72
4. Step 4: Simplify right side
   78.87x = 7,921.39
5. Step 5: Solve for x
   x = 7,921.39/78.87
6. Step 6: Final answer
   x = 100.44