Finding the Fourth Proportional to 1,389.98, 1,916.82 and 1,180.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.98 : 1,916.82 = 1,180.76 : x
2. Step 2: Convert to fraction form
   1,389.98/1,916.82 = 1,180.76/x
3. Step 3: Cross multiply
   1,389.98x = 1,916.82 × 1,180.76
4. Step 4: Simplify right side
   1,389.98x = 2,263,304.38
5. Step 5: Solve for x
   x = 2,263,304.38/1,389.98
6. Step 6: Final answer
   x = 1,628.30