Finding the Fourth Proportional to 1,405.30, 2,109.24 and 712.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.30 : 2,109.24 = 712.45 : x
2. Step 2: Convert to fraction form
   1,405.30/2,109.24 = 712.45/x
3. Step 3: Cross multiply
   1,405.30x = 2,109.24 × 712.45
4. Step 4: Simplify right side
   1,405.30x = 1,502,728.04
5. Step 5: Solve for x
   x = 1,502,728.04/1,405.30
6. Step 6: Final answer
   x = 1,069.33