Finding the Fourth Proportional to 2,557.67, 3,529.71 and 1,438.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,557.67 : 3,529.71 = 1,438.56 : x
2. Step 2: Convert to fraction form
   2,557.67/3,529.71 = 1,438.56/x
3. Step 3: Cross multiply
   2,557.67x = 3,529.71 × 1,438.56
4. Step 4: Simplify right side
   2,557.67x = 5,077,699.62
5. Step 5: Solve for x
   x = 5,077,699.62/2,557.67
6. Step 6: Final answer
   x = 1,985.29