Finding the Fourth Proportional to 5,128.55, 7,077.17 and 2,890.38

Step by Step Solution

1. Step 1: Write the proportion equation
   5,128.55 : 7,077.17 = 2,890.38 : x
2. Step 2: Convert to fraction form
   5,128.55/7,077.17 = 2,890.38/x
3. Step 3: Cross multiply
   5,128.55x = 7,077.17 × 2,890.38
4. Step 4: Simplify right side
   5,128.55x = 20,455,744.39
5. Step 5: Solve for x
   x = 20,455,744.39/5,128.55
6. Step 6: Final answer
   x = 3,988.60