Finding the Fourth Proportional to 1,439.63, 1,986.71 and 916.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.63 : 1,986.71 = 916.37 : x
2. Step 2: Convert to fraction form
   1,439.63/1,986.71 = 916.37/x
3. Step 3: Cross multiply
   1,439.63x = 1,986.71 × 916.37
4. Step 4: Simplify right side
   1,439.63x = 1,820,546.93
5. Step 5: Solve for x
   x = 1,820,546.93/1,439.63
6. Step 6: Final answer
   x = 1,264.60