WEEK 6 QUIZ
QUESTION 1
·
1/1 POINTS
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 100100 points was a x¯=77x¯=77, with a margin of error of 10.10.
Construct a confidence interval for the mean score (out of 100100 points) on the final
exam.
That is correct!
$$(67, 87)
Answer Explanation
Correct answers:
$\left(67,\ 87\right)$(67, 87)
A confidence interval is an interval of values, centered on a point estimate, of the form
(pointestimate−marginof error,pointestimate+marginof error)
(pointestimate−marginof error,pointestimate+marginof error)
Using the given point estimate for the mean, x¯=77x¯=77 and margin of error 1010,
the confidence interval is:
(77−10,77+10)(67,87)(77−10,77+10)(67,87)
FEEDBACK
Content attribution- Opens a dialog
, QUESTION 2
·
1/1 POINTS
A random sample of adults were asked whether they prefer reading an e-book over a
printed book. The survey resulted in a sample proportion of p′=0.14p′=0.14, with a
sampling standard deviation of σp′=0.02σp′=0.02, who preferred reading an e-book.
Use the empirical rule to construct a 95%95% confidence interval for the true
proportion of adults who prefer e-books.
That is correct!
$$(0.10, 0.18)
Answer Explanation
Correct answers:
$\left(0.10,\ 0.18\right)$(0.10, 0.18)
By the Empirical Rule, a 95%95% confidence interval corresponds to a zz-score
of z=2z=2. Substituting the given values p′=0.14p′=0.14 and σp′=0.02σp
′=0.02, a confidence interval is
(p′−z⋅σp′,p′+z⋅σp′)(0.14−2⋅0.02,0.14+2⋅0.02)
(0.14−0.04,0.14+0.04)(0.10,0.18)(p′−z⋅σp′,p′+z⋅σp′)
(0.14−2⋅0.02,0.14+2⋅0.02)(0.14−0.04,0.14+0.04)(0.10,0.18)
FEEDBACK
Content attribution- Opens a dialog
QUESTION 3
·
1/1 POINTS
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%95% confidence
interval of (237,293)(237,293) pages.
What is the correct interpretation of the 95%95% confidence interval?
That is correct!
QUESTION 1
·
1/1 POINTS
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 100100 points was a x¯=77x¯=77, with a margin of error of 10.10.
Construct a confidence interval for the mean score (out of 100100 points) on the final
exam.
That is correct!
$$(67, 87)
Answer Explanation
Correct answers:
$\left(67,\ 87\right)$(67, 87)
A confidence interval is an interval of values, centered on a point estimate, of the form
(pointestimate−marginof error,pointestimate+marginof error)
(pointestimate−marginof error,pointestimate+marginof error)
Using the given point estimate for the mean, x¯=77x¯=77 and margin of error 1010,
the confidence interval is:
(77−10,77+10)(67,87)(77−10,77+10)(67,87)
FEEDBACK
Content attribution- Opens a dialog
, QUESTION 2
·
1/1 POINTS
A random sample of adults were asked whether they prefer reading an e-book over a
printed book. The survey resulted in a sample proportion of p′=0.14p′=0.14, with a
sampling standard deviation of σp′=0.02σp′=0.02, who preferred reading an e-book.
Use the empirical rule to construct a 95%95% confidence interval for the true
proportion of adults who prefer e-books.
That is correct!
$$(0.10, 0.18)
Answer Explanation
Correct answers:
$\left(0.10,\ 0.18\right)$(0.10, 0.18)
By the Empirical Rule, a 95%95% confidence interval corresponds to a zz-score
of z=2z=2. Substituting the given values p′=0.14p′=0.14 and σp′=0.02σp
′=0.02, a confidence interval is
(p′−z⋅σp′,p′+z⋅σp′)(0.14−2⋅0.02,0.14+2⋅0.02)
(0.14−0.04,0.14+0.04)(0.10,0.18)(p′−z⋅σp′,p′+z⋅σp′)
(0.14−2⋅0.02,0.14+2⋅0.02)(0.14−0.04,0.14+0.04)(0.10,0.18)
FEEDBACK
Content attribution- Opens a dialog
QUESTION 3
·
1/1 POINTS
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%95% confidence
interval of (237,293)(237,293) pages.
What is the correct interpretation of the 95%95% confidence interval?
That is correct!
