MATH 225N Statistics Final Exam |
Questions And Answers 2026-2027 |
Already Graded A+ | 100%Guaranteed
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the number of goals scored in a hockey game -ANSWER discrete
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.
2.9, 5.7, 10.0, 13.2, 21.1. -ANSWER 7.5
Which measure of central tendency may not exist for all numeric data sets? -ANSWER
mode
Provide an appropriate response.
Civil engineers often use the straight-line equation, E(y) = β0 + β1x, to model the
relationship between the mean shear strength E(y) of masonry joints and
precompression stress, x. To test this theory, a series of stress tests were performed on
solid bricks arranged in triplets and joined with mortar. The precompression stress was
varied for each triplet and the ultimate shear load just before failure (called the shear
strength) was recorded. The stress results for n = 7 triplet tests is shown in the
accompanying table followed by a SAS printout of the regression analysis.
For this data set, R2 = .9052.
Give a practical interpretation of R2, the coefficient of determination for the least
squares model. Express R2 to the nearest whole percent. -ANSWER About 91% of the
total variation in the sample of y-values can be explained by (or attributed to) the linear
relationship between shear strength and precompression stress.
A traffic officer is compiling information about the relationship between the hour or the
day and the speed over the limit at which the motorist is ticketed. He computes a
correlation coefficient of 0.12. What does this tell the officer? -ANSWER There is a weak
positive linear correlation.
If the coefficient of determination is close to 1, then -ANSWER the least squares
regression line equation explains most of the variation in the response variable.
A variable that is related to either the response variable or the predictor variable or both,
but which is excluded from the analysis is a -ANSWER lurking variable
The coefficient of determination is the __________ of the linear correlation coefficient. -
ANSWER square
Provide an appropriate response.
Civil engineers often use the straight-line equation, E(y) = β0 + β1x, to model the
relationship between the mean shear strength E(y) of masonry joints and
precompression stress, x. To test this theory, a series of stress tests were performed on
solid bricks arranged in triplets and joined with mortar. The precompression stress was
varied for each triplet and the ultimate shear load just before failure (called the shear
Questions And Answers 2026-2027 |
Already Graded A+ | 100%Guaranteed
Pass!!
the number of goals scored in a hockey game -ANSWER discrete
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.
2.9, 5.7, 10.0, 13.2, 21.1. -ANSWER 7.5
Which measure of central tendency may not exist for all numeric data sets? -ANSWER
mode
Provide an appropriate response.
Civil engineers often use the straight-line equation, E(y) = β0 + β1x, to model the
relationship between the mean shear strength E(y) of masonry joints and
precompression stress, x. To test this theory, a series of stress tests were performed on
solid bricks arranged in triplets and joined with mortar. The precompression stress was
varied for each triplet and the ultimate shear load just before failure (called the shear
strength) was recorded. The stress results for n = 7 triplet tests is shown in the
accompanying table followed by a SAS printout of the regression analysis.
For this data set, R2 = .9052.
Give a practical interpretation of R2, the coefficient of determination for the least
squares model. Express R2 to the nearest whole percent. -ANSWER About 91% of the
total variation in the sample of y-values can be explained by (or attributed to) the linear
relationship between shear strength and precompression stress.
A traffic officer is compiling information about the relationship between the hour or the
day and the speed over the limit at which the motorist is ticketed. He computes a
correlation coefficient of 0.12. What does this tell the officer? -ANSWER There is a weak
positive linear correlation.
If the coefficient of determination is close to 1, then -ANSWER the least squares
regression line equation explains most of the variation in the response variable.
A variable that is related to either the response variable or the predictor variable or both,
but which is excluded from the analysis is a -ANSWER lurking variable
The coefficient of determination is the __________ of the linear correlation coefficient. -
ANSWER square
Provide an appropriate response.
Civil engineers often use the straight-line equation, E(y) = β0 + β1x, to model the
relationship between the mean shear strength E(y) of masonry joints and
precompression stress, x. To test this theory, a series of stress tests were performed on
solid bricks arranged in triplets and joined with mortar. The precompression stress was
varied for each triplet and the ultimate shear load just before failure (called the shear
