Finding the Fourth Proportional to 82.89, 124.35 and 28.78

Step by Step Solution

1. Step 1: Write the proportion equation
   82.89 : 124.35 = 28.78 : x
2. Step 2: Convert to fraction form
   82.89/124.35 = 28.78/x
3. Step 3: Cross multiply
   82.89x = 124.35 × 28.78
4. Step 4: Simplify right side
   82.89x = 3,578.79
5. Step 5: Solve for x
   x = 3,578.79/82.89
6. Step 6: Final answer
   x = 43.18