Answer:
a) P(2)=0.270
b) P(X>3)=0.605
c) P=0.410
Step-by-step explanation:
We know that customers arrive at a grocery store at an average of 2.1 per minute. We use the Poisson distribution:
a) In this case: 
Therefore, the probability is P(2)=0.270.
b) In this case: 
Therefore, the probability is P(X>3)=0.605.
c) We know that two customers came in in the first minute. That is why we calculate the probability of at least 5 customers entering the other 2 minutes.
In this case:
Therefore, the probability is P=0.410.
One way to do this is to notice
Then
We have
and since 
has a period of 
,
and so
Answer:
If Regina wants a mean of 90, she needs to sell 94 books on the 5th day.
You will need to set up and solve 2 equations:
A) 3 Vans + 10 Buses = 379
B) 14Vans + 13 Buses = 624
Multiply equation A by -14
A) -42 Vans -140 Buses = -5,306 then Multiply equation B by 3
B) 42 Vans + 39 Buses = 1,872
Adding BOTH equations
-101 Buses = -3,434
Each Bus holds 34 Students
Putting this into equation A
A) 3 Vans + 10 Buses = 379
A) 3 Vans + 10 * 34 = 379
A) 3 Vans +340 = 379
A) 3 Vans = 39
Each van = 13 students
A true or false question is a question that gives you a statement, and asks whether it's true (correct) or false (wrong).
