Finding the Fourth Proportional to 1,308.21, 1,805.37 and 718.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,308.21 : 1,805.37 = 718.79 : x
2. Step 2: Convert to fraction form
   1,308.21/1,805.37 = 718.79/x
3. Step 3: Cross multiply
   1,308.21x = 1,805.37 × 718.79
4. Step 4: Simplify right side
   1,308.21x = 1,297,681.90
5. Step 5: Solve for x
   x = 1,297,681.90/1,308.21
6. Step 6: Final answer
   x = 991.95