Finding the Fourth Proportional to 2,109.81, 2,911.54 and 1,178.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.81 : 2,911.54 = 1,178.31 : x
2. Step 2: Convert to fraction form
   2,109.81/2,911.54 = 1,178.31/x
3. Step 3: Cross multiply
   2,109.81x = 2,911.54 × 1,178.31
4. Step 4: Simplify right side
   2,109.81x = 3,430,696.70
5. Step 5: Solve for x
   x = 3,430,696.70/2,109.81
6. Step 6: Final answer
   x = 1,626.07