Finding the Fourth Proportional to 1,869.99, 2,580.71 and 1,239.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,869.99 : 2,580.71 = 1,239.43 : x
2. Step 2: Convert to fraction form
   1,869.99/2,580.71 = 1,239.43/x
3. Step 3: Cross multiply
   1,869.99x = 2,580.71 × 1,239.43
4. Step 4: Simplify right side
   1,869.99x = 3,198,609.40
5. Step 5: Solve for x
   x = 3,198,609.40/1,869.99
6. Step 6: Final answer
   x = 1,710.50