Finding the Fourth Proportional to 1,059.33, 1,462.17 and 639.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,059.33 : 1,462.17 = 639.72 : x
2. Step 2: Convert to fraction form
   1,059.33/1,462.17 = 639.72/x
3. Step 3: Cross multiply
   1,059.33x = 1,462.17 × 639.72
4. Step 4: Simplify right side
   1,059.33x = 935,379.39
5. Step 5: Solve for x
   x = 935,379.39/1,059.33
6. Step 6: Final answer
   x = 882.99