Finding the Fourth Proportional to 1,389.89, 1,913.67 and 1,179.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.89 : 1,913.67 = 1,179.63 : x
2. Step 2: Convert to fraction form
   1,389.89/1,913.67 = 1,179.63/x
3. Step 3: Cross multiply
   1,389.89x = 1,913.67 × 1,179.63
4. Step 4: Simplify right side
   1,389.89x = 2,257,412.97
5. Step 5: Solve for x
   x = 2,257,412.97/1,389.89
6. Step 6: Final answer
   x = 1,624.17