Finding the Fourth Proportional to 1,996.28, 2,756.10 and 1,288.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,996.28 : 2,756.10 = 1,288.47 : x
2. Step 2: Convert to fraction form
   1,996.28/2,756.10 = 1,288.47/x
3. Step 3: Cross multiply
   1,996.28x = 2,756.10 × 1,288.47
4. Step 4: Simplify right side
   1,996.28x = 3,551,152.17
5. Step 5: Solve for x
   x = 3,551,152.17/1,996.28
6. Step 6: Final answer
   x = 1,778.89