Finding the Fourth Proportional to 1,105.04, 1,658.25 and 643.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.04 : 1,658.25 = 643.03 : x
2. Step 2: Convert to fraction form
   1,105.04/1,658.25 = 643.03/x
3. Step 3: Cross multiply
   1,105.04x = 1,658.25 × 643.03
4. Step 4: Simplify right side
   1,105.04x = 1,066,300.35
5. Step 5: Solve for x
   x = 1,066,300.35/1,105.04
6. Step 6: Final answer
   x = 964.94