Finding the Fourth Proportional to 1,189.40, 1,783.18 and 670.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.40 : 1,783.18 = 670.89 : x
2. Step 2: Convert to fraction form
   1,189.40/1,783.18 = 670.89/x
3. Step 3: Cross multiply
   1,189.40x = 1,783.18 × 670.89
4. Step 4: Simplify right side
   1,189.40x = 1,196,325.16
5. Step 5: Solve for x
   x = 1,196,325.16/1,189.40
6. Step 6: Final answer
   x = 1,005.83