Finding the Fourth Proportional to 1,169.40, 1,613.72 and 645.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,169.40 : 1,613.72 = 645.42 : x
2. Step 2: Convert to fraction form
   1,169.40/1,613.72 = 645.42/x
3. Step 3: Cross multiply
   1,169.40x = 1,613.72 × 645.42
4. Step 4: Simplify right side
   1,169.40x = 1,041,527.16
5. Step 5: Solve for x
   x = 1,041,527.16/1,169.40
6. Step 6: Final answer
   x = 890.65