Finding the Fourth Proportional to 1,059.18, 1,461.33 and 639.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,059.18 : 1,461.33 = 639.48 : x
2. Step 2: Convert to fraction form
   1,059.18/1,461.33 = 639.48/x
3. Step 3: Cross multiply
   1,059.18x = 1,461.33 × 639.48
4. Step 4: Simplify right side
   1,059.18x = 934,491.31
5. Step 5: Solve for x
   x = 934,491.31/1,059.18
6. Step 6: Final answer
   x = 882.28