Finding the Fourth Proportional to 805.82, 1,111.85 and 491.25

Step by Step Solution

1. Step 1: Write the proportion equation
   805.82 : 1,111.85 = 491.25 : x
2. Step 2: Convert to fraction form
   805.82/1,111.85 = 491.25/x
3. Step 3: Cross multiply
   805.82x = 1,111.85 × 491.25
4. Step 4: Simplify right side
   805.82x = 546,196.31
5. Step 5: Solve for x
   x = 546,196.31/805.82
6. Step 6: Final answer
   x = 677.81