Finding the Fourth Proportional to 1,145.89, 1,581.23 and 673.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.89 : 1,581.23 = 673.80 : x
2. Step 2: Convert to fraction form
   1,145.89/1,581.23 = 673.80/x
3. Step 3: Cross multiply
   1,145.89x = 1,581.23 × 673.80
4. Step 4: Simplify right side
   1,145.89x = 1,065,421.50
5. Step 5: Solve for x
   x = 1,065,421.50/1,145.89
6. Step 6: Final answer
   x = 929.78