Probability problems

[kay_wink08]

A cruise ship has a 74% chance of having leftover rooms the week before the cruise. There are 25 cruise ships setting sail this month.
Is it possible to approximate this binomial distribution using a normal approximation?
What is the mean and the standard deviation for this approximation?
What is the probability that exactly 20 cruise ships will have leftover rooms using the normal approximation?
How different is the normal approximation from the binomial distribution value? Calculate the probability that exactly 20 cruise ships will have leftover rooms using the binomial method.

Pls help!!!!! thanks a lot!!

 

[Deleted member 4993]

A cruise ship has a 74% chance of having leftover rooms the week before the cruise. There are 25 cruise ships setting sail this month.
Is it possible to approximate this binomial distribution using a normal approximation?
What is the mean and the standard deviation for this approximation?
What is the probability that exactly 20 cruise ships will have leftover rooms using the normal approximation?
How different is the normal approximation from the binomial distribution value? Calculate the probability that exactly 20 cruise ships will have leftover rooms using the binomial method.

Pls help!!!!! thanks a lot!!

What are the equations for mean and the standard dev with the assumption of binomial distribution?

What are the equations for mean and the standard dev with the assumption of normal distribution?

Please share your work with us, indicating exactly where you are stuck - so that we may know where to begin to help you.

 

[kay_wink08]

Is it possible to approximate this binomial distribution using a normal approximation?
Yes it is possible because it is greater than 5.

What is the mean and the standard deviation for this approximation?
n = 25
? = ?(25) (0.74) (0.26)
? 0.22

What is the probability that exactly 20 cruise ships will have leftover rooms using the normal approximation?
P(X>20.5) = 1-P(X<20.5)
1-P(Z-(20.5-)/

This is what I got so far!!
what is the difference between normal approximation from the binomial distribution value??