Finding the Fourth Proportional to 1,907.28, 2,857.98 and 1,288.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,907.28 : 2,857.98 = 1,288.56 : x
2. Step 2: Convert to fraction form
   1,907.28/2,857.98 = 1,288.56/x
3. Step 3: Cross multiply
   1,907.28x = 2,857.98 × 1,288.56
4. Step 4: Simplify right side
   1,907.28x = 3,682,678.71
5. Step 5: Solve for x
   x = 3,682,678.71/1,907.28
6. Step 6: Final answer
   x = 1,930.85