Finding the Fourth Proportional to 1,067.77, 1,473.72 and 642.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,067.77 : 1,473.72 = 642.28 : x
2. Step 2: Convert to fraction form
   1,067.77/1,473.72 = 642.28/x
3. Step 3: Cross multiply
   1,067.77x = 1,473.72 × 642.28
4. Step 4: Simplify right side
   1,067.77x = 946,540.88
5. Step 5: Solve for x
   x = 946,540.88/1,067.77
6. Step 6: Final answer
   x = 886.47