STA 2381 Exam |Questions with Correct
Verified Answers
A study examined the economic rewards of obtaining an MBA degree. The researchers made
inferences based on wage data collected for a sample of individuals who sat for a particular
examination required for most MBA programs. The researchers used government wage data
for those who took the exam during a selected four-year time period, examining wage data
from a two-year period after degrees were obtained. Their wages were compared to those of
people who took the exam in the same period and did not obtain their degree. What method
was used to collect the sample data? - ANSWER The data were collected observationally.
A study examined the economic rewards of obtaining an MBA degree. The researchers made
inferences based on wage data collected for a sample of individuals who sat for a particular
examination required for most MBA programs. The researchers used government wage data for
those who took the exam during a selected four-year time period, examining wage data from a
two-year period after degrees were obtained. Their wages were compared to those of people
who took the exam in the same period and did not obtain their degree. Do you think the final
sample is representative of the population? Why or why not? Comment on potential biases in
the sample. - ANSWER Yes, because the data of all people who took the exam in the time
period were obtained.
A study examined the stress amounts of working additional hours. In the study, the researchers
investigated the link between weekly hours worked and stress level (measured on a 6-point
scale where 1= "not stressed and 6= "very stressed"). Participants for the study were those who
used a popular social networking Web site. The Web site's directory was searched for those
with "average" names (e.g. "John Smith", "Sara Jones"). These individuals were then invited to
participate in an online survey in exchange for a $20 gift certificate. Of the respondents, those
who worked very many or very few hours were excluded, leaving a sample size of 48
respondents. Identify the experimental units for this study. - ANSWER People who used a
particular Web site.
A study examined the stress amounts of working additional hours. In the study, the researchers
investigated the link between weekly hours worked and stress level (measured on a 6-point
, scale where 1= "not stressed and 6= "very stressed"). Participants for the study were those who
used a popular social networking Web site. The Web site's directory was searched for those
with "average" names (e.g. "John Smith", "Sara Jones"). These individuals were then invited to
participate in an online survey in exchange for a $20 gift certificate. Of the respondents, those
who worked very many or very few hours were excluded, leaving a sample size of 48
respondents. What are the variables of interest? Are they quantitative or qualitative in nature?
- ANSWER Weekly hours worked, quantitative; stress level, qualitative.
A study examined the stress amounts of working additional hours. In the study, the researchers
investigated the link between weekly hours worked and stress level (measured on a 6-point
scale where 1= "not stressed and 6= "very stressed"). Participants for the study were those
who used a popular social networking Web site. The Web site's directory was searched for
those with "average" names (e.g. "John Smith", "Sara Jones"). These individuals were then
invited to participate in an online survey in exchange for a $20 gift certificate. Of the
respondents, those who worked very many or very few hours were excluded, leaving a sample
size of 48 respondents. Describe the population of interest. - ANSWER All workers.
A study examined the stress amounts of working additional hours. In the study, the researchers
investigated the link between weekly hours worked and stress level (measured on a 6-point
scale where 1= "not stressed and 6= "very stressed"). Participants for the study were those who
used a popular social networking Web site. The Web site's directory was searched for those
with "average" names (e.g. "John Smith", "Sara Jones"). These individuals were then invited to
participate in an online survey in exchange for a $20 gift certificate. Of the respondents, those
who worked very many or very few hours were excluded, leaving a sample size of 48
respondents. Do you believe the sample of 48 respondents is representative of the population?
Explain. - ANSWER No, selection bias is present since only those with "average" names could
participate, and the group of these that did was self-selected.
Mean v Median v Mode - ANSWER The mean, median, and more are the most important
measures of central tendency. The mean of a data set is it's arithmetic average. The median of a
data set is the middle value in its ordered list. The mode of a data set is its most frequently
occurring value.
Mean v Median - ANSWER The mean is affected by extreme values, while the median is not.
If the data set is skewed to the right, then the median is less than the mean. If the data set is
symmetric, the mean equals the median. If the data set is skewed to the left, the mean is less
than the median.
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 KenAli. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.49. You're not tied to anything after your purchase.