Finding the Fourth Proportional to 89.21, 123.17 and 64.61

Step by Step Solution

1. Step 1: Write the proportion equation
   89.21 : 123.17 = 64.61 : x
2. Step 2: Convert to fraction form
   89.21/123.17 = 64.61/x
3. Step 3: Cross multiply
   89.21x = 123.17 × 64.61
4. Step 4: Simplify right side
   89.21x = 7,957.69
5. Step 5: Solve for x
   x = 7,957.69/89.21
6. Step 6: Final answer
   x = 89.20