Finding the Fourth Proportional to 1,399.28, 2,111.56 and 1,388.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.28 : 2,111.56 = 1,388.48 : x
2. Step 2: Convert to fraction form
   1,399.28/2,111.56 = 1,388.48/x
3. Step 3: Cross multiply
   1,399.28x = 2,111.56 × 1,388.48
4. Step 4: Simplify right side
   1,399.28x = 2,931,858.83
5. Step 5: Solve for x
   x = 2,931,858.83/1,399.28
6. Step 6: Final answer
   x = 2,095.26