Finding the Fourth Proportional to 1,579.82, 2,179.91 and 916.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,579.82 : 2,179.91 = 916.55 : x
2. Step 2: Convert to fraction form
   1,579.82/2,179.91 = 916.55/x
3. Step 3: Cross multiply
   1,579.82x = 2,179.91 × 916.55
4. Step 4: Simplify right side
   1,579.82x = 1,997,996.51
5. Step 5: Solve for x
   x = 1,997,996.51/1,579.82
6. Step 6: Final answer
   x = 1,264.70