Finding the Fourth Proportional to 89.31, 123.21 and 64.77

Step by Step Solution

1. Step 1: Write the proportion equation
   89.31 : 123.21 = 64.77 : x
2. Step 2: Convert to fraction form
   89.31/123.21 = 64.77/x
3. Step 3: Cross multiply
   89.31x = 123.21 × 64.77
4. Step 4: Simplify right side
   89.31x = 7,980.31
5. Step 5: Solve for x
   x = 7,980.31/89.31
6. Step 6: Final answer
   x = 89.36