Finding the Fourth Proportional to 2,123.60, 2,930.76 and 1,239.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.60 : 2,930.76 = 1,239.69 : x
2. Step 2: Convert to fraction form
   2,123.60/2,930.76 = 1,239.69/x
3. Step 3: Cross multiply
   2,123.60x = 2,930.76 × 1,239.69
4. Step 4: Simplify right side
   2,123.60x = 3,633,218.23
5. Step 5: Solve for x
   x = 3,633,218.23/2,123.60
6. Step 6: Final answer
   x = 1,710.88