Finding the Fourth Proportional to 1,309.30, 1,806.78 and 719.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,309.30 : 1,806.78 = 719.89 : x
2. Step 2: Convert to fraction form
   1,309.30/1,806.78 = 719.89/x
3. Step 3: Cross multiply
   1,309.30x = 1,806.78 × 719.89
4. Step 4: Simplify right side
   1,309.30x = 1,300,682.85
5. Step 5: Solve for x
   x = 1,300,682.85/1,309.30
6. Step 6: Final answer
   x = 993.42