Math 110 Module 9 Exam
Exam Page 1
Suppose you have 45 data points and you calculate the sample correlation coefficient and find that r
= .32. Can you be 95% confident that a linear relation exists between the variables? If so, is the
relation positive or negative? Justify you answer.
n = 45
r = .32 = |.32|
critical value = 0.2944
the absolute value is more than the critical value, there is a positive linear relationship.
-1.0 points
Instructor Comments
You can see the correct critical value in the Answer Key.
Answer Key
Suppose you have 45 data points and you calculate the sample correlation coefficient and find that r
= .32.Can you be 95% confident that a linear relation exists between the variables? If so, is the
relation positive or negative? Justify you answer.
Note that for n=45 and 95% we get a value from the chart of .29396. The absolute of r is |r|=.32,
which is above .29396. So a positive linear relation exists.
Exam Page 2
Suppose you have 34 data points and you calculate the sample correlation coefficient and find that r
= - .35. Can you be 95% confident that a linear relation exists between the variables? If so, is the
relation positive or negative? Justify you answer.
n = 24
r = -.35 = |.35|
critical value = 0.33879
, since the absolute value of r is negative and is lighter than the critical value, we can be 95% positive
that there is a negative linear relationship.
Instructor Comments
Very good.
Answer Key
Suppose you have 34 data points and you calculate the sample correlation coefficient and find that r
= - .35. Can you be 95% confident that a linear relation exists between the variables? If so, is the
relation positive or negative? Justify you answer.
Note that for n=34 and 95% we get a value from the chart of .33879. The absolute of r is |r|=.35,
which is above .33879. So a negative linear relation exists.
Exam Page 3
Compute the sample correlation coefficient for the following data:
Can you be 95% confident that a linear relation exists between the variables? If so, is the relation
positive or negative? Justify you answer.
n=5
r = .99
critical value = .87834
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LATESTSOLUTION. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.99. You're not tied to anything after your purchase.
