Finding the Fourth Proportional to 1,389.43, 1,918.02 and 970.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.43 : 1,918.02 = 970.39 : x
2. Step 2: Convert to fraction form
   1,389.43/1,918.02 = 970.39/x
3. Step 3: Cross multiply
   1,389.43x = 1,918.02 × 970.39
4. Step 4: Simplify right side
   1,389.43x = 1,861,227.43
5. Step 5: Solve for x
   x = 1,861,227.43/1,389.43
6. Step 6: Final answer
   x = 1,339.56