Thread: Statistics Question! Need help please!

1. Statistics Question! Need help please!

Hey guys. Can anybody please help me with this statistics question? THANKS

Question 1: On your shelf, you have four books that you are planning
to read in the near future. Two are ﬁctional works, containing 212 and 379
pages, respectively, and the other two are nonﬁction, with 350 and 575 pages,
respectively.
(a) (3 marks). Compute the population mean µ and standard deviation σ
of the (parent) population of number of pages of the four books.
(b) (8 marks). Suppose that you select a simple random sample of two
books from the four to take on a one-week ski trip (in case you injure
yourself). Let X¯ denote the sample mean number of pages for the two
books selected. Obtain the sampling distribution of X¯ for this sampling
method, and determine its mean and standard deviation.
(c) (8 marks). Suppose that you randomly select one of the two ﬁction
books and independently randomly select one of the two nonﬁction
books. Obtain the sampling distribution of X¯ for this sampling method,
and determine its mean and standard deviation.
(d) (4 marks). Which of these two sampling methods would you prefer for
making an educated guess about µ? Why?

2. Re: Statistics Question! Need help please!

specifically which part of the question do you not understand, or not know how to do?

3. Re: Statistics Question! Need help please!

Hey. I need to know how to do part d). I've done all the rest. Thanks alot!!!

4. Re: Statistics Question! Need help please!

Originally Posted by samishah
Hey guys. Can anybody please help me with this statistics question? THANKS

Question 1: On your shelf, you have four books that you are planning
to read in the near future. Two are ﬁctional works, containing 212 and 379
pages, respectively, and the other two are nonﬁction, with 350 and 575 pages,
respectively.
(a) (3 marks). Compute the population mean µ and standard deviation σ
of the (parent) population of number of pages of the four books.
(b) (8 marks). Suppose that you select a simple random sample of two
books from the four to take on a one-week ski trip (in case you injure
yourself). Let X¯ denote the sample mean number of pages for the two
books selected. Obtain the sampling distribution of X¯ for this sampling
method, and determine its mean and standard deviation.
(c) (8 marks). Suppose that you randomly select one of the two ﬁction
books and independently randomly select one of the two nonﬁction
books. Obtain the sampling distribution of X¯ for this sampling method,
and determine its mean and standard deviation.
(d) (4 marks). Which of these two sampling methods would you prefer for
making an educated guess about µ? Why?
Do you expect us to do your assignment for you?

5. Re: Statistics Question! Need help please!

Originally Posted by samishah
Hey. I need to know how to do part d). I've done all the rest. Thanks alot!!!
i believe the sampling method in c is better. simply put, if you took 2 random books out of the 4, you may easily get both fiction, or both non-fiction. and the fiction books have a smaller number of pages. if you selected both fiction, or both nonfiction, it won't give you an accurate picture of your population.