Finding the Fourth Proportional to 1,405.23, 2,109.15 and 712.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.23 : 2,109.15 = 712.39 : x
2. Step 2: Convert to fraction form
   1,405.23/2,109.15 = 712.39/x
3. Step 3: Cross multiply
   1,405.23x = 2,109.15 × 712.39
4. Step 4: Simplify right side
   1,405.23x = 1,502,529.42
5. Step 5: Solve for x
   x = 1,502,529.42/1,405.23
6. Step 6: Final answer
   x = 1,069.24