Finding the Fourth Proportional to 2,123.71, 2,930.99 and 1,239.53

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.71 : 2,930.99 = 1,239.53 : x
2. Step 2: Convert to fraction form
   2,123.71/2,930.99 = 1,239.53/x
3. Step 3: Cross multiply
   2,123.71x = 2,930.99 × 1,239.53
4. Step 4: Simplify right side
   2,123.71x = 3,633,029.18
5. Step 5: Solve for x
   x = 3,633,029.18/2,123.71
6. Step 6: Final answer
   x = 1,710.70