Finding the Fourth Proportional to 2,128.28, 3,189.34 and 1,513.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.28 : 3,189.34 = 1,513.20 : x
2. Step 2: Convert to fraction form
   2,128.28/3,189.34 = 1,513.20/x
3. Step 3: Cross multiply
   2,128.28x = 3,189.34 × 1,513.20
4. Step 4: Simplify right side
   2,128.28x = 4,826,109.29
5. Step 5: Solve for x
   x = 4,826,109.29/2,128.28
6. Step 6: Final answer
   x = 2,267.61