Finding the Fourth Proportional to 1,389.39, 1,907.31 and 1,192.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.39 : 1,907.31 = 1,192.56 : x
2. Step 2: Convert to fraction form
   1,389.39/1,907.31 = 1,192.56/x
3. Step 3: Cross multiply
   1,389.39x = 1,907.31 × 1,192.56
4. Step 4: Simplify right side
   1,389.39x = 2,274,578.93
5. Step 5: Solve for x
   x = 2,274,578.93/1,389.39
6. Step 6: Final answer
   x = 1,637.11