Finding the Fourth Proportional to 1,309.31, 1,806.89 and 719.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,309.31 : 1,806.89 = 719.88 : x
2. Step 2: Convert to fraction form
   1,309.31/1,806.89 = 719.88/x
3. Step 3: Cross multiply
   1,309.31x = 1,806.89 × 719.88
4. Step 4: Simplify right side
   1,309.31x = 1,300,743.97
5. Step 5: Solve for x
   x = 1,300,743.97/1,309.31
6. Step 6: Final answer
   x = 993.46