Finding the Fourth Proportional to 1,105.29, 1,525.43 and 639.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.29 : 1,525.43 = 639.54 : x
2. Step 2: Convert to fraction form
   1,105.29/1,525.43 = 639.54/x
3. Step 3: Cross multiply
   1,105.29x = 1,525.43 × 639.54
4. Step 4: Simplify right side
   1,105.29x = 975,573.50
5. Step 5: Solve for x
   x = 975,573.50/1,105.29
6. Step 6: Final answer
   x = 882.64