Finding the Fourth Proportional to 2,075.20, 3,112.14 and 688.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,075.20 : 3,112.14 = 688.28 : x
2. Step 2: Convert to fraction form
   2,075.20/3,112.14 = 688.28/x
3. Step 3: Cross multiply
   2,075.20x = 3,112.14 × 688.28
4. Step 4: Simplify right side
   2,075.20x = 2,142,023.72
5. Step 5: Solve for x
   x = 2,142,023.72/2,075.20
6. Step 6: Final answer
   x = 1,032.20