Finding the Fourth Proportional to 81.89, 122.68 and 43.33

Step by Step Solution

1. Step 1: Write the proportion equation
   81.89 : 122.68 = 43.33 : x
2. Step 2: Convert to fraction form
   81.89/122.68 = 43.33/x
3. Step 3: Cross multiply
   81.89x = 122.68 × 43.33
4. Step 4: Simplify right side
   81.89x = 5,314.89
5. Step 5: Solve for x
   x = 5,314.89/81.89
6. Step 6: Final answer
   x = 64.90