Finding the Fourth Proportional to 1,111.04, 1,533.32 and 639.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.04 : 1,533.32 = 639.08 : x
2. Step 2: Convert to fraction form
   1,111.04/1,533.32 = 639.08/x
3. Step 3: Cross multiply
   1,111.04x = 1,533.32 × 639.08
4. Step 4: Simplify right side
   1,111.04x = 979,919.58
5. Step 5: Solve for x
   x = 979,919.58/1,111.04
6. Step 6: Final answer
   x = 881.98