Finding the Fourth Proportional to 1,309.15, 1,806.60 and 719.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,309.15 : 1,806.60 = 719.68 : x
2. Step 2: Convert to fraction form
   1,309.15/1,806.60 = 719.68/x
3. Step 3: Cross multiply
   1,309.15x = 1,806.60 × 719.68
4. Step 4: Simplify right side
   1,309.15x = 1,300,173.89
5. Step 5: Solve for x
   x = 1,300,173.89/1,309.15
6. Step 6: Final answer
   x = 993.14