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Math chapter 1 test review

Terms in this set (20)

Match each type of bias to the definition
Sampling bias- When the techniques used to select individuals to be in the sample favor one part of the population over another.
Nonresponse Bias-When the individuals selected to be in the sample that do not respond to the survey have different opinions from those that do respond.
Response Bias- When the answers on a survey do not reflect the true feelings of the respondent.
Classify the variable as qualitative or quantitative. If the variable is​ quantitative, state whether it is discrete or continuous.
Weight in carats of an uncut diamond
Quantitative: Continuous
Suppose that a radio station
predicted that Candidate A would defeat Candidate B in a certain election. They conducted a poll of
automobile owners with a response rate of 25​%. On the basis of the​ results, the radio station
predicted that Candidate A would win with​ 57% of the popular vote.​ However, Candidate B won the election with about​ 62% of the popular vote. At the time of this​ poll, most automobile owners
belonged to the party of Candidate A. Name two biases that led to this incorrect prediction.
Sampling​ bias: Using an incorrect frame led to undercoverage.
Nonresponse​ bias: The low response rate caused bias.
Classify the variable as qualitative or quantitative. If the variable is​ quantitative, state whether it is discrete or continuous.
Brand name of a pair of running shoes
Qualitative
Determine whether the following study depicts an observational study or a designed experiment.
A sample of 504 patients in the early stages of a disease is divided into two groups. One group receives an experimental​ drug; the other receives a placebo. The advance of the disease in the patients from the two groups is tracked at​ 1-month intervals over the next year.
Experiment
Determine whether the quantitative variable is discrete or continuous.
Number of touchdowns thrown by a quarterback
The variable is discrete because it is countable
Determine the type of sampling used.
On election​ day, a pollster positions herself outside a polling place near her home and asks the first 50 voters leaving the facility to complete a survey.
Convenience Sample
Determine the type of sampling used.
An Internet service provider randomly selects 15 residential blocks from a large city and surveys every household in these 15 blocks to determine whether they use a​ high-speed Internet​ service, or not.
Cluster sample
Determine the type of sampling used.
Officers for the Department of Motor Vehicles pull aside every 40th tractor trailer passing through a weigh​ station, starting with the​ 12th, for an emissions test.
Systematic sample
A​ quality-control engineer wants to be sure that bolts coming off an assembly line are within prescribed tolerances. He wants to conduct a systematic sample by selecting every 7th bolt to come off the assembly line starting with the 6th
bolt. Identify the first five bolts to be selected.
6; 13; 20; 27; 34
Determine whether the variable is qualitative or quantitative.
Address
The variable is qualitative because it is an attribute characteristic
Determine whether the variable is qualitative or quantitative.
Favorite color
The variable is qualitative because it is an attribute characteristic
Match each word or phrase with its definition.
Statistics -This is the science of collecting, organizing, summarizing, and analyzing information to draw conclusions or answer questions. It is also about providing a measure of confidence in any conclusions.
Population -The entire group of individuals to be studied
The response variable- The variable of interest in the outcome of a study
A quantitative variable- This provides numerical measures of individuals. The values of these can be added or subtracted, and provide meaningful results.
A qualitative variable-Allow classification of individuals based on some attribute or characteristic
A variable- The characteristics of the individuals within the population
designed​ experiment - A researcher randomly assigns the individuals in a study to groups, intentionally manipulates the value of the explanatory variable and controls other explanatory variables at fixed values, and then records the value of the response variable for each individual.
observational​ study-A researcher measures the value of the response variable without attempting to influence the value of either the response or explanatory variables. That is, the researcher observes the behavior of individuals in the study and records the values of the explanatory and response variables.
lurking variable- This is an explanatory variable that was not considered in a study, but that affects the value of the response variable in the study. In addition, these are typically related to explanatory variables considered in the study.
Confounding-This occurs when the effects of two or more explanatory variables are not separated. Therefore, any relation that may exist between an explanatory variable and the response variable may be due to some other variable not accounted for in the study.
The methods of statistics follow a process. Place the processes in the correct order.
1. Identify the Research Objective
2. Collect the Data Needed to Answer the Research​ Question(s)
3. Describe the Data
4. Perform Inference
Classify the variable as qualitative or quantitative. If the variable is​ quantitative, state whether it is discrete or continuous.
Number of new automobiles sold at a dealership on a given day
Quantitative; discrete
Determine whether the underlined numerical value is a parameter or a statistic. Explain your reasoning.
In a survey of a sample of 1050 teenagers, 17% said they like to watch soccer.
Statistic, because the data set of a sample of 1050 teenagers is a sample.
Use the description of a study to complete parts​ (a) through​ (f) below.
​(a) What type of study is​ this?
(b) What are the treatments in the​ study?
(c) how many levels of treatment are in the study?
(d) what is the response variable in this study?
(e) which of the following were factors that were fixed at one level in this study? Select all that apply.
(f) identify the experimental units.
a. Completely-Randomized design
b. the type of gum or saliva
c. 4
d. percentage of stain removed
e. The amount of chewing: The temperature of the chewing device
f. the 64 bovine incisors
Determine whether the study depicts an observational study or an experiment.
Seventh-grade students are randomly divided into two groups. One group is taught math using traditional techniques; the other is taught math using a reform method.
After 1 year, each group is given an
achievement test to compare proficiency.
The study is an experiment because the researchers control one variable to determine the effect on the response variable.
Determine whether the following study depicts an observational study or a designed experiment.
Researchers looked at 8000 people and found that people who reported higher levels of satisfaction with their lives also had a lower risk of heart disease.
Observational study
The manager of a shopping mall wishes to expand the number of shops available in the food court.
He has a market researcher survey the first 120 customers who come into the food court during weekend
afternoons to determine what types of food the shoppers would like to see added to the food court. Complete parts​ (a) and​ (b) below.
(a) The survey has bias. Determine whether the flaw is due to the sampling method or the survey itself. For biased​ surveys, identify the cause of the error.
What is the cause of the​ bias?
Sampling bias
(b) Suggest a remedy to the problem.
Which of the following is the best way to remedy this​ problem? reword the question so that it is balanced
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