Finding the Fourth Proportional to 1,086.03, 1,498.69 and 643.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.03 : 1,498.69 = 643.93 : x
2. Step 2: Convert to fraction form
   1,086.03/1,498.69 = 643.93/x
3. Step 3: Cross multiply
   1,086.03x = 1,498.69 × 643.93
4. Step 4: Simplify right side
   1,086.03x = 965,048.51
5. Step 5: Solve for x
   x = 965,048.51/1,086.03
6. Step 6: Final answer
   x = 888.60