Finding the Fourth Proportional to 1,139.42, 1,705.84 and 669.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.42 : 1,705.84 = 669.47 : x
2. Step 2: Convert to fraction form
   1,139.42/1,705.84 = 669.47/x
3. Step 3: Cross multiply
   1,139.42x = 1,705.84 × 669.47
4. Step 4: Simplify right side
   1,139.42x = 1,142,008.70
5. Step 5: Solve for x
   x = 1,142,008.70/1,139.42
6. Step 6: Final answer
   x = 1,002.27