Finding the Fourth Proportional to 1,393.83, 1,921.89 and 1,309.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.83 : 1,921.89 = 1,309.08 : x
2. Step 2: Convert to fraction form
   1,393.83/1,921.89 = 1,309.08/x
3. Step 3: Cross multiply
   1,393.83x = 1,921.89 × 1,309.08
4. Step 4: Simplify right side
   1,393.83x = 2,515,907.76
5. Step 5: Solve for x
   x = 2,515,907.76/1,393.83
6. Step 6: Final answer
   x = 1,805.03