Finding the Fourth Proportional to 78.56, 108.22 and 74.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78.56 : 108.22 = 74.72 : x
2. Step 2: Convert to fraction form
   78.56/108.22 = 74.72/x
3. Step 3: Cross multiply
   78.56x = 108.22 × 74.72
4. Step 4: Simplify right side
   78.56x = 8,086.20
5. Step 5: Solve for x
   x = 8,086.20/78.56
6. Step 6: Final answer
   x = 102.93