
What is a population?
is any group in which a researcher is interested. A population can be large, such as all registered voters in San Joaquin County, or small such as all registered voters at San Joaquin Delta College.

What is a sample?
it is a smaller group culled from a population.

What is a statistic?
scores from a sample.

Descriptive statistics do what?
they summarize and describe data. For example, an average would be a descriptive statistic.
(Descriptive statistics are large numbers with data)

Inferential statistics do what?
they generalize from a population to a sample (inferring the sample is representative of the population)

What is a frequency?
the number of individuals or cases; its symbol is f.

What is a percentage?
indicates the number per hundred who have a certain characteristic; its symbol is P or %.

What is a proportion?
is a part of one signified by a fraction or decimal.

Scales of measurement are?
 N ominal (NAMING)
 O rdinal (ORDERING)
 I nterval (NO ZERO POINT)
 R atio (ZERO POINT)

Nominal is...?
(NAMING) A word scale of measurement listing by classification e.g. gender, race, age, etc.

Ordinal is..."
(ORDERING) A word scale of measurement listing by some degree of order or ranking e.g. mild, moderate, severe

Interval is...?
(NO ZERO POINT) A number scale of measurement noting equal distance with no meaningful zero point e.g. SAT scores from 200800

Ratio is...?
(ZERO POINT) A number scale of measurement noting equal distance with a meaningful zero point e.g. weight lost or gained, dollars in pocket

A frequency distribution ...?
shows how many individuals had each score, either individually or by score intervals

The symbol X stands for...?
the scores

A cumulative frequency ...?
indicates how many individuals are in and below a given score interval
 Formula:
 start at bottom with lowest score
 add next line up from f
 add from frequency all the way up.
 Top cf should be equal the sum of the f

Formula for percentage is...?
take f and divide by N

Formula for cumulative percentage...?
take cf and divide by N

Rounding off numbers are as follows:
 .075000 = .08 (to the nearest even #)
 .065000 = .06 (to the nearest even #)

