Finding the Fourth Proportional to 2,123.59, 2,930.91 and 1,239.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.59 : 2,930.91 = 1,239.39 : x
2. Step 2: Convert to fraction form
   2,123.59/2,930.91 = 1,239.39/x
3. Step 3: Cross multiply
   2,123.59x = 2,930.91 × 1,239.39
4. Step 4: Simplify right side
   2,123.59x = 3,632,534.35
5. Step 5: Solve for x
   x = 3,632,534.35/2,123.59
6. Step 6: Final answer
   x = 1,710.56