MATH 225N, Week 6 Quiz
, Week 6 Quiz
Question 1
A statistics professor recently graded final exams for students in her introductory statistics course. In a review
of her grading, she found the mean score out of 100 points was a x¯=77, with a margin of error of 10.
Construct a confidence interval for the mean score (out of 100 points) on the final exam.
That is correct!
Answer: (67, 87)
Question 2
A random sample of adults were asked whether they prefer reading an e-book over a printed book. The
survey resulted in a sample proportion of p′=0.14, with a sampling standard deviation of σp′=0.02, who
preferred reading an e-book.
Use the empirical rule to construct a 95% confidence interval for the true proportion of adults who prefer e-
books.
That is correct!
Answer: ( 0.10, 0.18)
Question 3
The pages per book in a library are normally distributed with an unknown population mean. A random sample
of books is taken and results in a 95% confidence interval of (237,293) pages.
What is the correct interpretation of the 95% confidence interval?
That is correct!
We estimate with 95% confidence that the sample mean is between 237 and 293 pages.
We estimate that 95% of the time a book is selected, there will be between 237 and 293 pages.
, Week 6 Quiz
Question 1
A statistics professor recently graded final exams for students in her introductory statistics course. In a review
of her grading, she found the mean score out of 100 points was a x¯=77, with a margin of error of 10.
Construct a confidence interval for the mean score (out of 100 points) on the final exam.
That is correct!
Answer: (67, 87)
Question 2
A random sample of adults were asked whether they prefer reading an e-book over a printed book. The
survey resulted in a sample proportion of p′=0.14, with a sampling standard deviation of σp′=0.02, who
preferred reading an e-book.
Use the empirical rule to construct a 95% confidence interval for the true proportion of adults who prefer e-
books.
That is correct!
Answer: ( 0.10, 0.18)
Question 3
The pages per book in a library are normally distributed with an unknown population mean. A random sample
of books is taken and results in a 95% confidence interval of (237,293) pages.
What is the correct interpretation of the 95% confidence interval?
That is correct!
We estimate with 95% confidence that the sample mean is between 237 and 293 pages.
We estimate that 95% of the time a book is selected, there will be between 237 and 293 pages.
