Finding the Fourth Proportional to 1,111.66, 1,533.94 and 639.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.66 : 1,533.94 = 639.52 : x
2. Step 2: Convert to fraction form
   1,111.66/1,533.94 = 639.52/x
3. Step 3: Cross multiply
   1,111.66x = 1,533.94 × 639.52
4. Step 4: Simplify right side
   1,111.66x = 980,985.31
5. Step 5: Solve for x
   x = 980,985.31/1,111.66
6. Step 6: Final answer
   x = 882.45