Finding the Fourth Proportional to 1,167.19, 1,610.72 and 643.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,167.19 : 1,610.72 = 643.25 : x
2. Step 2: Convert to fraction form
   1,167.19/1,610.72 = 643.25/x
3. Step 3: Cross multiply
   1,167.19x = 1,610.72 × 643.25
4. Step 4: Simplify right side
   1,167.19x = 1,036,098.86
5. Step 5: Solve for x
   x = 1,036,098.86/1,167.19
6. Step 6: Final answer
   x = 887.69