Finding the Fourth Proportional to 1,399.95, 2,100.18 and 669.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.95 : 2,100.18 = 669.57 : x
2. Step 2: Convert to fraction form
   1,399.95/2,100.18 = 669.57/x
3. Step 3: Cross multiply
   1,399.95x = 2,100.18 × 669.57
4. Step 4: Simplify right side
   1,399.95x = 1,406,217.52
5. Step 5: Solve for x
   x = 1,406,217.52/1,399.95
6. Step 6: Final answer
   x = 1,004.48