Finding the Fourth Proportional to 1,072.78, 1,609.50 and 448.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,072.78 : 1,609.50 = 448.38 : x
2. Step 2: Convert to fraction form
   1,072.78/1,609.50 = 448.38/x
3. Step 3: Cross multiply
   1,072.78x = 1,609.50 × 448.38
4. Step 4: Simplify right side
   1,072.78x = 721,665.37
5. Step 5: Solve for x
   x = 721,665.37/1,072.78
6. Step 6: Final answer
   x = 672.71