Final answer:
The average line length is approximately 3.
Step-by-step explanation:
To find the average line length, we need to calculate the value of p and then use it in the formula. First, we calculate p by dividing the average guest arrivals per minute (10) by the guests served per minute (11). This gives us p = 10/11 = 0.909 to 3 decimal places.
Now, we can substitute the value of p into the formula: p^2 / (2 x (1 - p)). Plugging in the value of p, we get 0.909^2 / (2 x (1 - 0.909)). Calculating this expression, we find that the average line length is approximately 3.