Finding the Third Proportional to 805.78 and 1,149.61

Step by Step Solution

1. Step 1: Write the proportion equation
   805.78 : 1,149.61 = 1,149.61 : x
2. Step 2: Convert to fraction form
   805.78/1,149.61 = 1,149.61/x
3. Step 3: Cross multiply
   805.78x = 1,149.61 × 1,149.61
4. Step 4: Simplify right side
   805.78x = 1,321,601.72
5. Step 5: Solve for x
   x = 1,321,601.72/805.78
6. Step 6: Final answer
   x = 1,640.15