Finding the Fourth Proportional to 1,580.99, 2,181.72 and 918.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,580.99 : 2,181.72 = 918.05 : x
2. Step 2: Convert to fraction form
   1,580.99/2,181.72 = 918.05/x
3. Step 3: Cross multiply
   1,580.99x = 2,181.72 × 918.05
4. Step 4: Simplify right side
   1,580.99x = 2,002,917.14
5. Step 5: Solve for x
   x = 2,002,917.14/1,580.99
6. Step 6: Final answer
   x = 1,266.88