Finding the Fourth Proportional to 1,579.98, 2,179.76 and 916.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,579.98 : 2,179.76 = 916.71 : x
2. Step 2: Convert to fraction form
   1,579.98/2,179.76 = 916.71/x
3. Step 3: Cross multiply
   1,579.98x = 2,179.76 × 916.71
4. Step 4: Simplify right side
   1,579.98x = 1,998,192.31
5. Step 5: Solve for x
   x = 1,998,192.31/1,579.98
6. Step 6: Final answer
   x = 1,264.70