Finding the Fourth Proportional to 72.79, 109.28 and 64.76

Step by Step Solution

1. Step 1: Write the proportion equation
   72.79 : 109.28 = 64.76 : x
2. Step 2: Convert to fraction form
   72.79/109.28 = 64.76/x
3. Step 3: Cross multiply
   72.79x = 109.28 × 64.76
4. Step 4: Simplify right side
   72.79x = 7,076.59
5. Step 5: Solve for x
   x = 7,076.59/72.79
6. Step 6: Final answer
   x = 97.22