Finding the Third Proportional to 813.80 and 1,259.72

Step by Step Solution

1. Step 1: Write the proportion equation
   813.80 : 1,259.72 = 1,259.72 : x
2. Step 2: Convert to fraction form
   813.80/1,259.72 = 1,259.72/x
3. Step 3: Cross multiply
   813.80x = 1,259.72 × 1,259.72
4. Step 4: Simplify right side
   813.80x = 1,586,891.33
5. Step 5: Solve for x
   x = 1,586,891.33/813.80
6. Step 6: Final answer
   x = 1,949.98