Finding the Fourth Proportional to 72.79, 109.18 and 68.56

Step by Step Solution

1. Step 1: Write the proportion equation
   72.79 : 109.18 = 68.56 : x
2. Step 2: Convert to fraction form
   72.79/109.18 = 68.56/x
3. Step 3: Cross multiply
   72.79x = 109.18 × 68.56
4. Step 4: Simplify right side
   72.79x = 7,485.38
5. Step 5: Solve for x
   x = 7,485.38/72.79
6. Step 6: Final answer
   x = 102.84