Finding the Fourth Proportional to 1,105.24, 1,525.38 and 639.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.24 : 1,525.38 = 639.52 : x
2. Step 2: Convert to fraction form
   1,105.24/1,525.38 = 639.52/x
3. Step 3: Cross multiply
   1,105.24x = 1,525.38 × 639.52
4. Step 4: Simplify right side
   1,105.24x = 975,511.02
5. Step 5: Solve for x
   x = 975,511.02/1,105.24
6. Step 6: Final answer
   x = 882.62