Finding the Fourth Proportional to 1,439.93, 1,986.28 and 997.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.93 : 1,986.28 = 997.07 : x
2. Step 2: Convert to fraction form
   1,439.93/1,986.28 = 997.07/x
3. Step 3: Cross multiply
   1,439.93x = 1,986.28 × 997.07
4. Step 4: Simplify right side
   1,439.93x = 1,980,447.78
5. Step 5: Solve for x
   x = 1,980,447.78/1,439.93
6. Step 6: Final answer
   x = 1,375.38