Finding the Fourth Proportional to 1,438.98, 1,985.52 and 809.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,438.98 : 1,985.52 = 809.43 : x
2. Step 2: Convert to fraction form
   1,438.98/1,985.52 = 809.43/x
3. Step 3: Cross multiply
   1,438.98x = 1,985.52 × 809.43
4. Step 4: Simplify right side
   1,438.98x = 1,607,139.45
5. Step 5: Solve for x
   x = 1,607,139.45/1,438.98
6. Step 6: Final answer
   x = 1,116.86