Finding the Fourth Proportional to 1,438.56, 2,158.56 and 668.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,438.56 : 2,158.56 = 668.96 : x
2. Step 2: Convert to fraction form
   1,438.56/2,158.56 = 668.96/x
3. Step 3: Cross multiply
   1,438.56x = 2,158.56 × 668.96
4. Step 4: Simplify right side
   1,438.56x = 1,443,990.30
5. Step 5: Solve for x
   x = 1,443,990.30/1,438.56
6. Step 6: Final answer
   x = 1,003.77