40 terms

bekind213TEACHER

Statistics

The science of collection, processing, organizing, summarizing, analyzing, presentation, and interpretation of data.

Datum

Past and present tense for data

data

the raw values that we work with in statistics

data

We obtain ____ by taking measurements, by counting, by asking questions, and by using already published information.

data set

a collection of data values

variable

a characteristic or feature that can assume different values

descriptive statistics

What consists of the collection, organization, summarization and presentation of data? (this is based on actual reports, not on probability of things past)

Inferential statistics

What is the part of statistics that develop generalizations about populations based on data from samples that determines relations between variables and that uses the data to make predictions? (uses probability)

population

the set that contains all of the subjects that are being studied. The subjects may be people....***

sample

a group (set) of subjects selected from the population being studied. The subjects may be people, animals, or other things.

statistical inference

a prediction or generalization made based on the given data

quantitative variables

variables whose values (subjects) are numbers. They can be ordered or ranked according to size.

qualitative variables

variables that have objects or things as subjects

discrete variables

these variables represent data values that can be counted such as the number of kids, streets, carts, etc. (Can you count it?)

continuous variables

these variables represent data values like time, distance, weight and temperature (*between any two data values, there are an infinite number of data values)

measured, rounded

Continuous data must be m_______ and most measurements must be r_______ because of the limitations of the measuring devices.

surveys

What are the most common method of collecting data?

telephone, questionnaire, interview, observation

The four most common methods of surveying are: t_______ surveys, mailed q________ surveys, personal i______ surveys, and direct o________ surveys.

random sample

a sample in which each element of the population has an equal chance of being selected.

biased sample

a sample that is not representative of the population from which it was taken

systematic sampling

a sample that is obtained by selecting every Kth data value of the population; "k" is a counting number.

systematic sample process

What involves the process of numbering each object, then dividing the number of the last object by the size of the sample desired to find what the Kth number we will use. Select a number from one *****

stratified sample

the sample is obtained by first dividing the population into subgroups called strata, and then selecting subjects from each subgroup to form a sample.

cluster sample

the sample that is obtained by first dividing the population into clusters (sections), then selecting one or more clusters and using the members of those clusters as the sample

sampling error

the difference between the results obtained from a sample and the results obtained from the corresponding population

observational study

a researcher observes the subjects in the study and draws conclusions based on what he saw

experimental study

the researcher manipulates one of the variables in the study in hopes of determining how this manipulation influences other variables

independent variable

What is the variable that the researcher manipulates in an experimental study?

dependent variable

a variable in correlation and regression analysis that cannot be controlled or manipulated

control group

When doing an experimental study, researchers need something to compare the group that is being manipulated. This creates the need for a second group called the ______ g_____. ****(listen for more info) This group is not given any special treatment.

Suspect samples (?)

There are different types of statistical distortion that can occur. They are "ambiguous averages", "changing the subject", "detached statistics" and "implied connections", "misleading graphs" and "faulty survey questions".

detached statistics

When something is presented such as "one third fewer calories" but it doesn't state what it is comparing it to.

5

Boundaries: The process for boundaries is: To calculate, add and subtract an extra decimal to the number using __as the value. If the number is 86, the boundaries would be 85.5 and 86.5. This is interpreted to mean: 85.5 is less than or equal to a number that is also LESS than 86.5.

45.665, 45.675

Boundaries: If a number is 45.67, the boundaries would be ____(##) and ____(##).

nominal, ordinal, interval, ratio

The four levels of measurement are n______, o_____, i______, and r_____.

nominal

A level of measurement: classifies data into mutually exclusive categories in which the data cannot be ordered or ranked. There is not ranking or order that can be placed on the data. (Such as classifying according to school subject, or male/female, or zip codes, or political party, or type of religion or marital status, car color)

ordinal

A level of measurement: classifies data into categories that can be ranked but there are no precise differences between the ranks. (subject may be ranked by superior, average or poor)

interval

A level of measurement: the data can be ranked and there are precise differences between data type (such as an IQ test, where there is a meaningful difference of one point between IQ of 109 and IQ of 110) BUT there is no meaningful zero (There is no true zero. IQ tests do not measure people who have no intelligence, and a temperature of 0 degrees does not mean no heat at all.)

ratio

A level of measurement: the data can be ranked and there are precise differences between data and there IS a true meaningful ZERO. (height, weight, counting things like number of phone calls received)

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