Answer:
-7
Step-by-step explanation:
 
        
                    
             
        
        
        
Like the other answer said. desmos all the way
 
        
        
        
Answer: There are 4 average cars in the system.
Step-by-step explanation:
Since we have given that 
Arrival rate = λ = 4 cars per hour
Service rate = μ = 5 cars per hour
We need to find the average number of cars in the system.
So, Average number of cars would be 

So, it becomes,

Hence, there are 4 average cars in the system.
 
        
             
        
        
        
Unbiased. If it was biased then she would only choose people she wanted to answer her survey. It is unbiased because she is asking the first 10 random people who walk into her shop.