Finding the Fourth Proportional to 1,399.41, 1,929.76 and 979.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.41 : 1,929.76 = 979.63 : x
2. Step 2: Convert to fraction form
   1,399.41/1,929.76 = 979.63/x
3. Step 3: Cross multiply
   1,399.41x = 1,929.76 × 979.63
4. Step 4: Simplify right side
   1,399.41x = 1,890,450.79
5. Step 5: Solve for x
   x = 1,890,450.79/1,399.41
6. Step 6: Final answer
   x = 1,350.89