Finding the Fourth Proportional to 1,038.52, 1,433.09 and 645.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,038.52 : 1,433.09 = 645.47 : x
2. Step 2: Convert to fraction form
   1,038.52/1,433.09 = 645.47/x
3. Step 3: Cross multiply
   1,038.52x = 1,433.09 × 645.47
4. Step 4: Simplify right side
   1,038.52x = 925,016.42
5. Step 5: Solve for x
   x = 925,016.42/1,038.52
6. Step 6: Final answer
   x = 890.71