Exam 1 review

1953 1962 1977 1979 1980 1987 1995 2001 2005

Interval the data can be ordered and differences between data entries but a zero is not an inherent zero

Why is a sample used more often than a population?

It is usually impossible to count the entire population

How often do you eat fast food during an average month?

No because it does not lead the respondent to any particular answer

Gone girl Private London The racketeer Kiss the dead Spring fever

Nominal date are categorised using names labels or qualities but data cannot be ranked or arranged in order

6. 16. 69. 18. 19. 5. 11 7. 22. 20. 24. 13. 10. 17 2. 8. 4. 14. 21. 36. 34. 42. 28. 25. 15. 89. 3.

Nominal date are categorised using numbers but no mathematical computation can be made

Nominal data scale

Nominal means 'by name' and used in classification or division of objects into discrete groups. Each of which is identified with a name e.g. category of cars, and the scale does not provide any measurement within or between categories.

The average age of men who have walked on the moon was 39 years, 11 months, 15 days

Parameter

1.Southeast 2.eastern 3.Southwest 4.Northeast 5.western 6.northern

Qualitative Ordinal

Favourite sport

Qualitative because a favorite sport describes an attribute or characteristics

The number of cars for 10 households in a neighbourhood of 30 households

Sample because the collection of the number of cars for 10 households in a subset of all households in the neighbourhood.

In a survey of 1266 adults in a country, 56% said the country's leader should release all medical information that might affect their ability to serve

The study is observational because it does not apply a treatment to the adults

Colors of automobiles

The variable is qualitative because colors are attributes or labels

A population is the collection of all outcomes, response, measurements, or counts that are of interest

True

Parcel tracking numbers

Variable is qualitative because tracking numbers are attributes or labels

interval scale

measurement in which the assigned numbers legitimately allow the comparison of the size of the differences among and between members

ratio scale

measurement that has a natural, or absolute, zero and therefore allows the comparison of absolute magnitudes of the numbers

What is the difference between a parameter and a statistic?

A parameter is a numerical measurement describing data from a population. A statistic is a numerical measurement describing data from a sample.

How is a sample related to a population?

A sample is a subset of a population.

Age Temperature Change in health Family history of illness

Age - ratio Change in health (ordinal) Temperature- interval Family of history of illness- nominal

After a flood a disaster area is divided into 250 equal grids. Fifty of the grids are selected and every occupied household in the grid is interviewed to help focus relief efforts on what residents require the most

Cluster sampling is used since the disaster area is divided into grids and some of those grids are selected and everyone in those grids is interviewed Bias Certain grids may have been much more severely damaged than others. The grids that are selected may not be representative in terms of damage. Certain grids may have been much more severely damaged than others. Severely damaged grids may have fewer occupied households

Questioning students as they leave an athletic facility a researcher asks 344 students about their dating habits

Convenience sampling is used because students are chosen due to convenience of location Bias Because of the personal nature of the question students may not answer honestly The sample only consists of members of the population that are easy to get. These members may not be representative of the population.

The heights of home owners in a certain country. The heights of home owners in the country who have a garage

Description of the population; the heights of home owners in the country Description of the sample; the heights of home owners in the country who have a garage

Suppose a survey of 559 women in the United States found that more than 55% are the primary investor in their household. Which part of the survey represents the descriptive branch of statistics?

Descriptive statistics- 55% of women in the sample are the primary investor in their households Ineference- there is an association between US women and being primary investor in their household

The salary of each baseball player in a league

Population because it is a collection of salaries for all baseball players in plague

The number of restaurants in each city in a state

Population because it is a collection of the number of restaurants for all cities in the state

A survey of 144 law firms in a country found that the average hourly billing rate for partners was $592

Population- all law firms in the country Sample- the law firms that were surveyed Sample data set- the average hourly billing rate for partners of 144 law firms was $592

In a poll 1003 men in country were asked whether they favor or oppose the the use of "federal tax dollars to fund medical research using stem cells obtained from human embryos". Among the respondents 47% said they were in favor.

Population- all men in country Sample- the 1003 men selected

In 1965 researchers used random digit dialing to call 1000 people and ask what obstacles kept them from sleeping 8 hours a night

Simple random sampling was used since each number had an equal chance of being dialed so all samples of 1000 phone numbers had an equal chance of being selected Individuals may have refused to participate in the sample Telephone sampling only includes people who has telephones Individuals may have not been available when the researcher were calling

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 sample

A company has been rating television programs for more than 60 years it uses several sampling procedures but its main one is to track the viewing patterns of 20,000 households. These contain more than 45,000 people and are chosen to form a cross section of the overall population. The household represent various locations, ethnic groups, and income brackets. The data gathered from the sample of 20,000 households are used to draw inferences about the population of all households in the United States

Strata- the various locations, ethnic groups, and income brackets that are represented Importance- stratified sampling ensures that each segment of the population is represented

Soybeans are planted on a 54 acre field. The field is divided into one acre subplots. A sample is taken from each subplot to estimate the harvest

Stratified sampling is used since the field is divided into subplots abs a random sample is taken from each subplot Bias Certain subjects may have more or fewer soybean plants than others. Samples from these subplots may bias the overall sample

Every sixteenth person entering a sporting goods store is asked to choose his or her favorite sport from a list of five different sports that includes a description of each

Systematic sampling is used because every sixteenth person is selected Bias The wording of the question may be direct respondents towards a particular sport If there is a regular pattern to the people entering the sporting goods store, the sample may not be representative

A pharmaceutical company wants to test the effectiveness of a new allergy drug. The company identifies 250 females 30-35 years old who suffer from severe allergies. The subjects are randomly assigned into two groups. One group is given the new allergy drug and the other given a placebo that looks exactly like the new allergy drug. After six months the subjects symptoms are studied and compared.

The experimental units are the 30-35 year old females being given the treatment. The treatment is the new allergy drug. There may be a bias on the part of the researcher if the researcher knows which patients were given the real drug. The study would be a double blind study if both the researcher and the patient did not know which patient received the real drug or the placebo

A survey of 2214 adults in a country found that 79% think that militant terrorists are a major threat to the well being of their country

The number is a sample of statistics because it describes the people in a sample which is a subset of all of the people in the country

Why is drinking soda bad for you ?

The question is biased. The wording "How do you think drinking soda affects your health?" would be better

It is impossible for the Census Bereau to obtain all the census data about the population of the United States

The statement is true

The study affects of social media on teenagers brain researchers showed a few dozen teenagers photographs that had varying numbers of "likes" while scanning the reactions in their brains

The study is an experiment because it applies a treatment to the teenagers

ordinal scale

a rank order measurement scale

What are the two main branches of statistics?

descriptive statistics and inferential statistics