Finding the Fourth Proportional to 72.89, 109.21 and 64.72

Step by Step Solution

1. Step 1: Write the proportion equation
   72.89 : 109.21 = 64.72 : x
2. Step 2: Convert to fraction form
   72.89/109.21 = 64.72/x
3. Step 3: Cross multiply
   72.89x = 109.21 × 64.72
4. Step 4: Simplify right side
   72.89x = 7,068.07
5. Step 5: Solve for x
   x = 7,068.07/72.89
6. Step 6: Final answer
   x = 96.97