Finding the Fourth Proportional to 1,389.25, 1,917.03 and 940.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.25 : 1,917.03 = 940.21 : x
2. Step 2: Convert to fraction form
   1,389.25/1,917.03 = 940.21/x
3. Step 3: Cross multiply
   1,389.25x = 1,917.03 × 940.21
4. Step 4: Simplify right side
   1,389.25x = 1,802,405.98
5. Step 5: Solve for x
   x = 1,802,405.98/1,389.25
6. Step 6: Final answer
   x = 1,297.40