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49 Cards in this Set
- Front
- Back
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A(n) ___ is a person or object that is a member of the population being studied. |
individual |
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A(n) ___ is a numerical summary of a sample. |
statistic |
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A(n) ___ is a numerical summary of a population. |
parameter |
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Determine whether the value is a parameter or a statistic: In a national survey on substance abuse, 66.4% of respondents who were full-time college students aged 18 to 22 reported using alcohol within the past month. |
The value is a statistic because the respondents are a sample. |
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Determine whether the variable is qualitative or quantitative: Amount of money won in a lottery. |
It is quantitative because it is a numerical measure. |
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Determine whether the variable is qualitative or quantitative: Amount of money spent on CDs this year. |
It is quantitative because it is a numerical measure. |
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Determine whether the quantitative variable is discrete or continuous: Field goals attempted by a kicker. |
The variable is discrete because it is countable. |
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Determine whether the quantitative variable is discrete or continuous: Width of a plank of wood.
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The variable is continuous because it is not countable. |
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Determine the level of measurement of the variable: Favorite type of music. a) nominal b) ratio c) ordinal d) interval |
a) nominal |
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Determine the level of measurement of the variable: Height of a child - 25 in, 26 in, 27 in, 28 in, and 29 in.
a) nominal b) ratio c) ordinal d) interval |
b) ration |
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What is the population and the sample in the study? A polling organization contacts 2021 adult men who are 40 to 60 years of age and live in the U.S... |
population - adult men 40 to 60 years of age and live in the U.S. sample - 2021 adult men 40 to 60 years of age and live in the U.S. |
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Determine whether each variable is qualitative, continuous, or discrete: size of a television, screen type of a television, and number of available channels. |
a) continuous b) qualitative c) discrete |
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Explain what is meant when it is said that "data vary". How does this variability affect the results of statistical analysis? a) Saying "data vary" means that examining different types of subjects will yield different data, such as examining a person and examining a car. Because data vary, it is impossible to compare different types of subjects, such as comparing people and cars. b) Saying "data vary" means that the values of the variable change from individual to individual. In addition, certain variables can change over time for certain individuals. Because data vary, two different statistical analysis of the same variable can lead to different results. c) Saying "data vary" means that observations can be measured with fractions or decimals instead of only integers. Because data vary, it is important to make sure to accurately account for fractional observations. |
b) Saying "data vary" means that the values of the variable change from individual to individual. In addition, certain variables can change over time for certain individuals. Because data vary, two different statistical analysis of the same variable can lead to different results. |
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What is an observational study? a) An observational study is when a researcher assigns individuals to a certain group, intentionally changing the value of an explanatory variable, and then recording the value of the response variable for each group. b) An observational study is a list of all individuals in a population along with certain characteristics of each individual. c) An observational study measures the value of the response variable without attempting to influence the value of either the response or explanatory variables. |
c) An observational study measures the value of the response variable without attempting to influence the value of either the response or explanatory variables.
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What is a designed experiment? a) A designed experiment measures the value of the response variable without attempting to influence the value of either the response or explanatory variables. b) A designed experiment is when a researcher assigns individuals to a certain group, intentionally changing the value of an explanatory variable, and then recording the value of the response variable for each group. c) A designed experiment is a list of all individuals in a population along with certain characteristics of each individual. |
b) A designed experiment is when a researcher assigns individuals to a certain group, intentionally changing the value of an explanatory variable, and then recording the value of the response variable for each group. |
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Does an observation or a designed experiment allow a researcher to claim causation between an explanatory variable and a response variable? |
a designed experiment |
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An observational study or an experiment: A poll is conducted by a school's math department in which sixth-grade students are asked if they prefer to be in math or English class. |
The study is an observational study because the study examines individuals in a sample, but does not try to influence the response variable. |
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An observational study or an experiment: 50 patients on aspirin are divided into two groups. One group is treated with a new anti-nuclear drug. The other is not. After one month, both groups are questioned about their stomach pain. |
The study is an experiment because the researchers control one variable to determine the effect on the response variable. |
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Define simple random sampling. a) Simple random sampling is the process of using chance to select individuals from a population to be included in the sample. The sample is then called a simple random sample. b) Simple random sampling is the process of obtaining a sample of size n from a population of the same size n. The sample is then called a simple random sample. c) A sample of size n from a population of size N is obtained through simple random sampling if every possible sample of size n has an equally likely chance of occurring. The sample is then called a simple random sample. |
c) A sample of size n from a population of size N is obtained through simple random sampling if every possible sample of size n has an equally likely chance of occurring. The sample is then called a simple random sample. |
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Which sampling method does not require a frame? a) simple random b) cluster c) stratified d) systematic |
d) systematic |
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A(n) ___ is obtained by dividing the population into homogeneous groups and randomly selecting individuals from each group. |
stratified sample |
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To determine customer opinion of their check-in service, AA randomly selects 110 flights during a certain week and surveys all passengers on the flights. What type of sampling is used? a) stratified b) simple random c) systematic d) cluster e) convenience |
d) cluster |
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Sony wants to administer a satisfaction survey to its current customers. Using their customer database, the company randomly selects 70 customers and asks them about their level of satisfaction with the company. What type of sampling is used? a) stratified b) simple random c) systematic d) cluster e) convenience |
b) simple random |
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What does it mean when a part of the population is under-represented?
a) A part of the population is under-represented when it is proportionally smaller in a sample than in its population. b) A part of the population is under-represented when individuals selected to be in the sample who do not respond to the survey have different opinions from those who do. c) A part of the population is under-represented when the technique used to obtain the individuals to be in the sample tends to favor one part of the population over another. |
a) A part of the population is under-represented when it is proportionally smaller in a sample than in its population. |
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Define experimental unit. a) A person, object, or some other well-defined item upon which a treatment is applied b) An innocuous medication, such as a sugar tablet, that looks, tastes, and smells like the experimental medication c) The quantitative or qualitative variable for which the experimenter wishes to determine how its value is affected by the explanatory variable |
a) A person, object, or some other well-defined item upon which a treatment is applied |
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Define treatment. a) The quantitative or qualitative variable for which the experimenter wishes to determine how its value is affected by the explanatory variable b) Any combination of the values of the factors (explanatory variables) c) A controlled study to determine the effect varying one or more explanatory variables or factors has on a response variable |
b) Any combination of the values of the factors (explanatory variables) |
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Define response variable. a)The variable whose effect on the response variable is to be assessed by the experimenter b) The quantitative or qualitative variable for which the experimenter wishes to determine how its value is affected by the explanatory variable c) The effect of two factors (explanatory variables on the response variable) cannot be distinguished. |
b) The quantitative or qualitative variable for which the experimenter wishes to determine how its value is affected by the explanatory variable |
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Define factor. a) A variable whose effect on the response variable is to be assessed by the experimenter b) A controlled study to determine the effect varying one or more explanatory variables or factors has on a response variable c) Grouping together similar experimental units |
a) A variable whose effect on the response variable is to be assessed by the experimenter |
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Define confounding. a) A controlled study to determine the effect varying one or more explanatory variables or factors has on a response variable b) Grouping together similar experimental units c) The effect of two factors (explanatory variables on the response variable) cannot be distinguished. |
c) The effect of two factors (explanatory variables on the response variable) cannot be distinguished. |
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True or False: Observational studies can be used to determine causality between explanatory and response variables. |
False |
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True or False: Generally, the goal of an experiment is to determine the effect that the treatment will have on the response variable. |
True |
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A frequency distribution lists the ___ of occurrences of each category of data, which a relative frequency distribution lists the ___ of occurrences of each category of data. |
number, proportion |
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Suppose a person claims that, "2.6% of all people in the nation always eat out." Is this a descriptive or inferential statement? |
inferential |
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Does it make sense to draw a pie chart for land area? |
Yes |
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Does it make sense to draw a pie chart for the highest land elevation? |
No |
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What does it mean if a statistic is resistant? a) Extreme values (very large or small) relative to the data affect its value substantially. b) Changing particular data values affects its value substantially. c) Extreme values (very large or small) relative to the data do not affect its value substantially. d) An estimate of its value is extremely close to its actual value. |
c) Extreme values (very large or small) relative to the data do not affect its value substantially. |
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What makes the range less desirable than the standard deviation as a measure of dispersion? a) The range describes how far, on average, each observation is from the mean. b) The range is biased. c) The range does not use all the observations. |
c) The range does not use all the observations. |
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What does it mean to say that two variables are positively associated? a) There is a linear relationship between the variables, and whenever the value of one variable increases, the value of the other variable decreases. b) There is a relationship between the variables that is not linear. c) There is a linear relationship between the variables, and whenever the value of one variable increases, the value of the other variable increases. |
c) There is a linear relationship between the variables, and whenever the value of one variable increases, the value of the other variable increases. |
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Do the following variables have a positive correlation, negative correlation, or no correlation? The number of doctors on staff at a hospital and the number of administrators on staff. |
positive correlation |
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Do the following variables have a positive correlation, negative correlation, or no correlation? The number of cigarettes smoked by a pregnant woman each week and the birth weight of her baby.
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negative correlation |
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What does it mean if r = 0? a) No linear relationship exists between the variables. b)No relationship exists between the variables. c) A linear relationship does exist between the variables. |
a) No linear relationship exists between the variables. |
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What is a residual? What does it mean when a residual is positive? a) A residual is a data point that does not fit the pattern of the rest of the data. If it is positive, then the data point should still be included in the data set. b) A residual is the difference between an observed value of the response variable y and the predicted value of y. If it is positive, then the observed value is greater than the predicted value. c) A residual is the difference between an observed value of the response variable y and the value of the corresponding explanatory variable x. If it is positive, then the response variable is greater than the explanatory variable. |
b) A residual is the difference between an observed value of the response variable y and the predicted value of y. If it is positive, then the observed value is greater than the predicted value. |
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Determine whether the events E and F are independent or dependent: E - A person attaining a position as a professor. F - The same person attaining a PhD |
E and F are dependent because attaining a PhD can affect the probability of a person attaining a position as a professor. |
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Determine whether the events E and F are independent or dependent:
E - A randomly selected person having a high GPA F - Another randomly selected person having a low GPA |
E and F are independent because the people were randomly selected. |
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Determine whether the events E and F are independent or dependent:
E -The consumer demand for synthetic diamonds. F - The amount of research funding for diamond synthesis. |
E and F are dependent because the consumer demand could affect the amount of research funding. |
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Maytag wants to administer a satisfaction survey to its current customers. Using their customer database, the company randomly selects 30 customers and asks them about their level of satisfaction with the company.
a) cluster b) convenience c) simple random d) systematic e) stratified |
c) simple random |
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Why is it rare for frames to be completely accurate? a) It is rare for frames to be accurate because frames are obtained periodically, whereas populations are constantly changing. b) It is rare for frames to be accurate because large sample sizes used in frames almost always result in data-entry errors. c) It is rare for frames to be accurate because individuals that were selected to be in the sample do not always respond to the survey, which can create non-response bias. d) It is rare for frames to be accurate because frames are obtained in a way that causes the sample to favor one part of the population over another. |
a) It is rare for frames to be accurate because frames are obtained periodically, whereas populations are constantly changing.
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If a factor cannot be controlled, what should be done to reduce variability in the response variable?
a) Experimental units should not be randomized to each treatment group. b) Experimental units should be randomized to each treatment group. c) It is necessary to use another experimental design. |
b) Experimental units should be randomized to each treatment group.
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Explain the Law of Large Numbers. How does this law apply to gambling casinos?
a) As the number of repetitions of a probability experiment increases, the proportion with which a certain outcome is observed gets closer to the probability of the outcome. This applies to casinos because they are able to make a profit in the long run because they have a small statistical advantage in each game. b) As the number of repetitions of a probability experiment increases, the proportion with which a certain outcome is observed gets closer to the probability of the outcome. Casinos use the Law of Large Numbers to determine how many players gamble in certain games. c) As the number of repetitions of a probability experiment increases, the proportion with which a certain outcome is observed gets closer to 1. This applies to casinos because they are able to make a profit in the long run because they have a small statistical advantage in each game. |
a) As the number of repetitions of a probability experiment increases, the proportion with which a certain outcome is observed gets closer to the probability of the outcome. This applies to casinos because they are able to make a profit in the long run because they have a small statistical advantage in each game.
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