A motel finds that 65% of customers who book will subsequently send a deposit...

sensational

sensational

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A motel finds that 65% of customers who book will subsequently send a deposit to confirm the booking. If they receive 300 bookings,
1. calculate the mean of the number of customers who send a deposit.
2. find the standard deviation of the number of customers who send a deposit.

Mean =195 I cant find the standard deviation?


 
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sensational said:
A motel finds that 65% of customers who book will subsequently send a deposit to confirm the booking. If they receive 300 bookings,
1. calculate the mean of the number of customers who send a deposit.
2. find the standard deviation of the number of customers who send a deposit.

Mean =195 I cant find the standard deviation?
Click to expand...
Me either with the information given.
 
Can't we find the variance first so that we can take its root to find a standard deviation. I know this is a stupid question but this question during the Test, One of our fellow classmates finds the standard deviation = 8.261. Amazingly he was the only person to solve the problem. If the question contains not enough information, HOW DID HE FINDS THE ANSWER. I have been working on this problem privately for hours until I put it on this site for help as soon as I found out I can't find the standard deviation. If you Ishuda can't help who else can cause our Teacher says "We can solve it." IF he is right maybe theres a way and someone around here can help with it. Please if you have read this try to solve it yourself who knows its you who can solve the problem.
 
sensational said:
Can't we find the variance first so that we can take its root to find a standard deviation. I know this is a stupid question but this question during the Test, One of our fellow classmates finds the standard deviation = 8.261. Amazingly he was the only person to solve the problem. If the question contains not enough information, HOW DID HE FINDS THE ANSWER. I have been working on this problem privately for hours until I put it on this site for help as soon as I found out I can't find the standard deviation. If you Ishuda can't help who else can cause our Teacher says "We can solve it." IF he is right maybe theres a way and someone around here can help with it. Please if you have read this try to solve it yourself who knows its you who can solve the problem.
Click to expand...

If all of the information given for the problem was in your initial post, then I suggest you ask your instructor how to find the standard deviation and solve the problem [and I, for one, would be interested in the answer of how the standard deviation was found]. With the information given, from my stand point a standard deviation of \(\displaystyle \sqrt{60}\) is just as good as the other students 8.261.
 
Ishuda said:
If all of the information given for the problem was in your initial post, then I suggest you ask your instructor how to find the standard deviation and solve the problem [and I, for one, would be interested in the answer of how the standard deviation was found]. With the information given, from my stand point a standard deviation of \(\displaystyle \sqrt{60}\) is just as good as the other students 8.261.
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Ishuda, I see your message yesterday, and Today I've just come back and heres how he solved the Problem let n=300, p=0.65, q=0.35 where n=total number of customers who send a deposit, n=P(customers who send a deposit),q=P(customers who do not) So if you take the roots of npq=standard deviation=8.261
 
sensational said:
Ishuda, I see your message yesterday, and Today I've just come back and heres how he solved the Problem let n=300, p=0.65, q=0.35 where n=total number of customers who send a deposit, n=P(customers who send a deposit),q=P(customers who do not) So if you take the roots of npq=standard deviation=8.261
Click to expand...

The additional information then is that the number of customers who book that will subsequently send a deposit to confirm the booking is distributed as the binomial distribution and that is not in the original problem as posed. I guess your teacher expects the students to assume it is a binomial distribution. I just hope next time the instructor does assume that it is a Poisson distribution and therefore the standard deviation is \(\displaystyle \sqrt{195}\).

But that doesn't help you. Sorry 'bout that.
 
Thank You Ishuda.

Ishuda said:
The additional information then is that the number of customers who book that will subsequently send a deposit to confirm the booking is distributed as the binomial distribution and that is not in the original problem as posed. I guess your teacher expects the students to assume it is a binomial distribution. I just hope next time the instructor does assume that it is a Poisson distribution and therefore the standard deviation is \(\displaystyle \sqrt{195}\). But that doesn't help you. Sorry 'bout that.
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You've been helping alot Ishuda. I didn't even know this question is a Binomial or a Poisson distribution. Because if I know i would already found its formula If it is a Poisson I wil use σ=\(\displaystyle \sqrt{λ}\), λ=µ. And if it is a Binomial I will use σ=\(\displaystyle \sqrt{µ(1-π}\),.....\(\displaystyle {µ=nπ}\). Problem solved :D
 
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