Finding the Fourth Proportional to 1,405.42, 2,109.43 and 712.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.42 : 2,109.43 = 712.58 : x
2. Step 2: Convert to fraction form
   1,405.42/2,109.43 = 712.58/x
3. Step 3: Cross multiply
   1,405.42x = 2,109.43 × 712.58
4. Step 4: Simplify right side
   1,405.42x = 1,503,123.96
5. Step 5: Solve for x
   x = 1,503,123.96/1,405.42
6. Step 6: Final answer
   x = 1,069.52