Finding the Fourth Proportional to 78.56, 117.72 and 72.56

Step by Step Solution

1. Step 1: Write the proportion equation
   78.56 : 117.72 = 72.56 : x
2. Step 2: Convert to fraction form
   78.56/117.72 = 72.56/x
3. Step 3: Cross multiply
   78.56x = 117.72 × 72.56
4. Step 4: Simplify right side
   78.56x = 8,541.76
5. Step 5: Solve for x
   x = 8,541.76/78.56
6. Step 6: Final answer
   x = 108.73