Finding the Fourth Proportional to 1,613.56, 2,228.27 and 1,390.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,613.56 : 2,228.27 = 1,390.42 : x
2. Step 2: Convert to fraction form
   1,613.56/2,228.27 = 1,390.42/x
3. Step 3: Cross multiply
   1,613.56x = 2,228.27 × 1,390.42
4. Step 4: Simplify right side
   1,613.56x = 3,098,224.25
5. Step 5: Solve for x
   x = 3,098,224.25/1,613.56
6. Step 6: Final answer
   x = 1,920.12