Finding the Fourth Proportional to 1,109.94, 1,660.68 and 669.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.94 : 1,660.68 = 669.57 : x
2. Step 2: Convert to fraction form
   1,109.94/1,660.68 = 669.57/x
3. Step 3: Cross multiply
   1,109.94x = 1,660.68 × 669.57
4. Step 4: Simplify right side
   1,109.94x = 1,111,941.51
5. Step 5: Solve for x
   x = 1,111,941.51/1,109.94
6. Step 6: Final answer
   x = 1,001.80