Finding the Fourth Proportional to 5,128.50, 7,077.32 and 2,890.28

Step by Step Solution

1. Step 1: Write the proportion equation
   5,128.50 : 7,077.32 = 2,890.28 : x
2. Step 2: Convert to fraction form
   5,128.50/7,077.32 = 2,890.28/x
3. Step 3: Cross multiply
   5,128.50x = 7,077.32 × 2,890.28
4. Step 4: Simplify right side
   5,128.50x = 20,455,436.45
5. Step 5: Solve for x
   x = 20,455,436.45/5,128.50
6. Step 6: Final answer
   x = 3,988.58