Finding the Fourth Proportional to 1,389.22, 1,916.76 and 923.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.22 : 1,916.76 = 923.47 : x
2. Step 2: Convert to fraction form
   1,389.22/1,916.76 = 923.47/x
3. Step 3: Cross multiply
   1,389.22x = 1,916.76 × 923.47
4. Step 4: Simplify right side
   1,389.22x = 1,770,069.03
5. Step 5: Solve for x
   x = 1,770,069.03/1,389.22
6. Step 6: Final answer
   x = 1,274.15