Finding the Fourth Proportional to 1,436.31, 2,158.07 and 916.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,436.31 : 2,158.07 = 916.55 : x
2. Step 2: Convert to fraction form
   1,436.31/2,158.07 = 916.55/x
3. Step 3: Cross multiply
   1,436.31x = 2,158.07 × 916.55
4. Step 4: Simplify right side
   1,436.31x = 1,977,979.06
5. Step 5: Solve for x
   x = 1,977,979.06/1,436.31
6. Step 6: Final answer
   x = 1,377.13