Finding the Fourth Proportional to 1,167.32, 1,610.86 and 643.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,167.32 : 1,610.86 = 643.35 : x
2. Step 2: Convert to fraction form
   1,167.32/1,610.86 = 643.35/x
3. Step 3: Cross multiply
   1,167.32x = 1,610.86 × 643.35
4. Step 4: Simplify right side
   1,167.32x = 1,036,346.78
5. Step 5: Solve for x
   x = 1,036,346.78/1,167.32
6. Step 6: Final answer
   x = 887.80