An economist conducted a study of the possible association between weekly income and
weekly grocery expenditures. The particular interest was whether higher income would cause
shoppers to spend more on groceries. A random sample of shoppers at a local supermarket
was obtained. A questionnaire was administered asking about the weekly income of each
shopper's family and their grocery bill for that week. The gender of each shopper was also
obtained. The relationship between grocery expenditure and income was assessed by
calculating both a correlation for the females only and a correlation for the males only. For the
females, r = 0.45 and for the males, r = 0.38. We conclude that: - ANS-the relationship between
grocery expenditures and income is stronger for females.
What can be said of the correlation between the brand of an automobile and its quality? -
ANS-Correlation makes no sense here, because brand is a categorical variable.
An economist conducted a study of the possible association between weekly income and
weekly grocery expenditures. The particular interest was whether higher income would result in
shoppers spending more on groceries. A random sample of shoppers at a local supermarket
was obtained, and a questionnaire was administered asking about the weekly income of the
shopper's family and the grocery bill for that week. The gender of the shopper was also
obtained. The correlation was found to be r = 0.8056. The amount of variation in the response
explained by the regression line is: - ANS-64.9%
The volume of oxygen consumed (in liters per minute) while a person is at rest and while a
person is exercising (running on a treadmill) were both measured for 50 subjects. The goal is to
determine if the volume of oxygen consumed during aerobic exercise can be estimated from the
amount consumed at rest. The results are plotted below. The scatterplot suggests that there is: -
ANS-both a positive association between volume of oxygen consumed at rest and while
running, and an outlier in the plot.
An economist conducted a study of the possible association between weekly income and
weekly grocery expenditures. Of particular interest was whether higher income would result in
shoppers spending more on groceries. A random sample of shoppers at a local supermarket
was obtained. A questionnaire was administered asking about the weekly income of each
shopper's family and their grocery bill for that week. The explanatory variable is: - ANS-weekly
income
Frequent food questionnaires (FFQ) are a simple way to obtain information on the foods
individuals consume by asking them questions about typical amounts of food consumed in a
day, a week, or a month. A more accurate picture is obtained by obtaining a detailed food diary
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 EFT, 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 this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller topgradesdr. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R148,20. You're not tied to anything after your purchase.