Finding the Fourth Proportional to 1,167.05, 1,610.37 and 643.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,167.05 : 1,610.37 = 643.10 : x
2. Step 2: Convert to fraction form
   1,167.05/1,610.37 = 643.10/x
3. Step 3: Cross multiply
   1,167.05x = 1,610.37 × 643.10
4. Step 4: Simplify right side
   1,167.05x = 1,035,620.90
5. Step 5: Solve for x
   x = 1,035,620.90/1,167.05
6. Step 6: Final answer
   x = 887.38