Finding the Fourth Proportional to 1,308.25, 1,805.42 and 718.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,308.25 : 1,805.42 = 718.80 : x
2. Step 2: Convert to fraction form
   1,308.25/1,805.42 = 718.80/x
3. Step 3: Cross multiply
   1,308.25x = 1,805.42 × 718.80
4. Step 4: Simplify right side
   1,308.25x = 1,297,735.90
5. Step 5: Solve for x
   x = 1,297,735.90/1,308.25
6. Step 6: Final answer
   x = 991.96