Finding the Fourth Proportional to 1,439.28, 2,157.12 and 1,026.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.28 : 2,157.12 = 1,026.18 : x
2. Step 2: Convert to fraction form
   1,439.28/2,157.12 = 1,026.18/x
3. Step 3: Cross multiply
   1,439.28x = 2,157.12 × 1,026.18
4. Step 4: Simplify right side
   1,439.28x = 2,213,593.40
5. Step 5: Solve for x
   x = 2,213,593.40/1,439.28
6. Step 6: Final answer
   x = 1,537.99