Finding the Fourth Proportional to 2,109.84, 2,911.56 and 1,178.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.84 : 2,911.56 = 1,178.40 : x
2. Step 2: Convert to fraction form
   2,109.84/2,911.56 = 1,178.40/x
3. Step 3: Cross multiply
   2,109.84x = 2,911.56 × 1,178.40
4. Step 4: Simplify right side
   2,109.84x = 3,430,982.30
5. Step 5: Solve for x
   x = 3,430,982.30/2,109.84
6. Step 6: Final answer
   x = 1,626.18