MATH 225N FINAL EXAM 2 2026 EXAM-STYLE
QUESTIONS AND MODEL RESPONSES
◉ A scientist was studying the effects of a new fertilizer on crop
yield. She randomly assigned half of the plots on a farm to group one
and the remaining plots to group two. On the plots in group one, the
new fertilizer was used for a year. On the plots in group two, the old
fertilizer was used. At the end of the year the average crop yield for
the plots in group one was compared with the average crop yield for
the plots in group two.. Answer: experiment
◉ Identify the type of sampling used.
A travel industry researcher interviews all of the passengers on five
randomly selected cruises. What sampling technique is used?.
Answer: cluster
◉ Identify the type of sampling used.
A lobbyist for the oil industry assigns a number to each senator and
then uses a computer to randomly generate ten numbers. The
lobbyist contacts the senators corresponding to these numbers.
What sampling technique was used?. Answer: simple random
,◉ Determine what type of observational study is described. Explain.
Researchers wanted to determine whether there was an association
between high blood pressure and the suppression of emotions. The
researchers looked at 1800 adults enrolled in a Health Initiative
Observational Study. Each person was interviewed and asked about
their response to emotions. In particular they were asked whether
their tendency was to express or to hold in anger and other
emotions. The degree of suppression of emotions was rated on a
scale of 1 to 10. Each person's blood pressure was also measured.
The researchers analyzed the results to determine whether there
was an association between high blood pressure and the
suppression of emotions.. Answer: cross-sectional; Information is
collected at a specific point in time.
◉ Identify the type of sampling used.
Thirty-five math majors, 47 music majors and 51 history majors are
randomly selected from 376 math majors, 591 music majors and
267 history majors at the state university. What sampling technique
is used?. Answer: stratified
◉ Determine what type of observational study is described. Explain.
Researchers wanted to determine whether there was an association
between high blood pressure and the suppression of emotions. The
,researchers looked at 1800 adults enrolled in a Health Initiative
Observational Study. Each person was interviewed and asked about
their response to emotions. In particular they were asked whether
their tendency was to express or to hold in anger and other
emotions. The degree of suppression of emotions was rated on a
scale of 1 to 10. Each person's blood pressure was also measured.
The researchers analyzed the results to determine whether there
was an association between high blood pressure and the
suppression of emotions.. Answer: cross-sectional; Information is
collected at a specific point in time.
◉ Provide an appropriate response.
Multiple choice questions on a test that include as one of the choices
"none of the above" are an example of what type of question?.
Answer: closed question
◉ Classify the variable as qualitative or quantitative.
the number of calls received at a company's help desk. Answer:
quantitative
◉ Provide an appropriate response.
, The following data are the yields, in bushels, of hay from a farmer's
last 10 years:
375, 210, 150, 147, 429, 189, 320, 580, 407, 180.
Find the IQR.. Answer: 227
◉ Provide an appropriate response.
Over the last 10 years four mutual funds all had the same mean rate
of return, 12%. These mutual funds had different standard
deviations as follows: Mutual Money 8%, Co-joined Investments 6%,
Together Fund 4%, All for One Fund 9%. Which mutual fund
investment is the most consistent in rate of return?. Answer:
Together Fund
◉ Provide an appropriate response.
Last year batting averages in professional baseball averaged 0.256
with a high of and a low of (minimum 250 at-bats). Based on this
information, which measure of variation could be calculated?.
Answer: range
◉ Provide an appropriate response.
Given the following five-number summary, find the IQR.
QUESTIONS AND MODEL RESPONSES
◉ A scientist was studying the effects of a new fertilizer on crop
yield. She randomly assigned half of the plots on a farm to group one
and the remaining plots to group two. On the plots in group one, the
new fertilizer was used for a year. On the plots in group two, the old
fertilizer was used. At the end of the year the average crop yield for
the plots in group one was compared with the average crop yield for
the plots in group two.. Answer: experiment
◉ Identify the type of sampling used.
A travel industry researcher interviews all of the passengers on five
randomly selected cruises. What sampling technique is used?.
Answer: cluster
◉ Identify the type of sampling used.
A lobbyist for the oil industry assigns a number to each senator and
then uses a computer to randomly generate ten numbers. The
lobbyist contacts the senators corresponding to these numbers.
What sampling technique was used?. Answer: simple random
,◉ Determine what type of observational study is described. Explain.
Researchers wanted to determine whether there was an association
between high blood pressure and the suppression of emotions. The
researchers looked at 1800 adults enrolled in a Health Initiative
Observational Study. Each person was interviewed and asked about
their response to emotions. In particular they were asked whether
their tendency was to express or to hold in anger and other
emotions. The degree of suppression of emotions was rated on a
scale of 1 to 10. Each person's blood pressure was also measured.
The researchers analyzed the results to determine whether there
was an association between high blood pressure and the
suppression of emotions.. Answer: cross-sectional; Information is
collected at a specific point in time.
◉ Identify the type of sampling used.
Thirty-five math majors, 47 music majors and 51 history majors are
randomly selected from 376 math majors, 591 music majors and
267 history majors at the state university. What sampling technique
is used?. Answer: stratified
◉ Determine what type of observational study is described. Explain.
Researchers wanted to determine whether there was an association
between high blood pressure and the suppression of emotions. The
,researchers looked at 1800 adults enrolled in a Health Initiative
Observational Study. Each person was interviewed and asked about
their response to emotions. In particular they were asked whether
their tendency was to express or to hold in anger and other
emotions. The degree of suppression of emotions was rated on a
scale of 1 to 10. Each person's blood pressure was also measured.
The researchers analyzed the results to determine whether there
was an association between high blood pressure and the
suppression of emotions.. Answer: cross-sectional; Information is
collected at a specific point in time.
◉ Provide an appropriate response.
Multiple choice questions on a test that include as one of the choices
"none of the above" are an example of what type of question?.
Answer: closed question
◉ Classify the variable as qualitative or quantitative.
the number of calls received at a company's help desk. Answer:
quantitative
◉ Provide an appropriate response.
, The following data are the yields, in bushels, of hay from a farmer's
last 10 years:
375, 210, 150, 147, 429, 189, 320, 580, 407, 180.
Find the IQR.. Answer: 227
◉ Provide an appropriate response.
Over the last 10 years four mutual funds all had the same mean rate
of return, 12%. These mutual funds had different standard
deviations as follows: Mutual Money 8%, Co-joined Investments 6%,
Together Fund 4%, All for One Fund 9%. Which mutual fund
investment is the most consistent in rate of return?. Answer:
Together Fund
◉ Provide an appropriate response.
Last year batting averages in professional baseball averaged 0.256
with a high of and a low of (minimum 250 at-bats). Based on this
information, which measure of variation could be calculated?.
Answer: range
◉ Provide an appropriate response.
Given the following five-number summary, find the IQR.
