Finding the Fourth Proportional to 1,167.28, 1,610.82 and 643.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,167.28 : 1,610.82 = 643.30 : x
2. Step 2: Convert to fraction form
   1,167.28/1,610.82 = 643.30/x
3. Step 3: Cross multiply
   1,167.28x = 1,610.82 × 643.30
4. Step 4: Simplify right side
   1,167.28x = 1,036,240.51
5. Step 5: Solve for x
   x = 1,036,240.51/1,167.28
6. Step 6: Final answer
   x = 887.74