Finding the Fourth Proportional to 1,109.73, 1,665.57 and 646.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.73 : 1,665.57 = 646.87 : x
2. Step 2: Convert to fraction form
   1,109.73/1,665.57 = 646.87/x
3. Step 3: Cross multiply
   1,109.73x = 1,665.57 × 646.87
4. Step 4: Simplify right side
   1,109.73x = 1,077,407.27
5. Step 5: Solve for x
   x = 1,077,407.27/1,109.73
6. Step 6: Final answer
   x = 970.87