Finding the Fourth Proportional to 1,099.82, 1,649.73 and 643.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,099.82 : 1,649.73 = 643.50 : x
2. Step 2: Convert to fraction form
   1,099.82/1,649.73 = 643.50/x
3. Step 3: Cross multiply
   1,099.82x = 1,649.73 × 643.50
4. Step 4: Simplify right side
   1,099.82x = 1,061,601.26
5. Step 5: Solve for x
   x = 1,061,601.26/1,099.82
6. Step 6: Final answer
   x = 965.25