Finding the Fourth Proportional to 1,174.29, 1,620.59 and 643.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,174.29 : 1,620.59 = 643.23 : x
2. Step 2: Convert to fraction form
   1,174.29/1,620.59 = 643.23/x
3. Step 3: Cross multiply
   1,174.29x = 1,620.59 × 643.23
4. Step 4: Simplify right side
   1,174.29x = 1,042,408.89
5. Step 5: Solve for x
   x = 1,042,408.89/1,174.29
6. Step 6: Final answer
   x = 887.69