Stats Ch1

the science of planning studies and experiments, obtaining sample data, and then organizing, summarizing, analyzing, interpreting data, and drawing conclusions about a population based on the data

the collection of observations (such as measurements, genders, survey responses---data values)

• the complete collection of all individuals (scores, people, measurements, and so
• on) to be studied; the collection is complete in the sense that it includes all of the individuals to be studied

a numerical measurement describing some characteristic of a population.

a numerical measurement describing some characteristic of sample data

Qualitative! also called attribute; consists of names or labels

data that consists only of names, labels, or categories. Cannot be listed in quantitative schemes, such as low to high.

Survey responses (yes, no, undecided)

data that can be arranged in a degree of order, but differences between data values cannot be determined or are meaningless. No actual values are attributed.

Grades: A, B, C... (but not saying what distinguishes an A from a B, etc)

data when the number of possible values is a finite (countable) number

the number of eggs that a hen lays

data that results from infinitely many possible values that correspond to some continuous scale that covers a range of values without gaps.

shows how a data set if partitioned among all of several categories by listing all of the categories along with the number of data values in each of the categories

a graph consisting of bars of equal width drawn adjacent to each other (without gaps)

• measures variation among data values
• has the same units of measurement as the original data
• A value is typically unusual if it differs from the mean by more than two standard deviations
• Only compare standard deviation of two different data sets if they have means that  are approximately the same.

describes the standard deviation, relative to the mean

cv (coefficient value) = sd/mean *100%

measures of location that divide a set into four groups. There are three quartiles, so think of them as the lines between divisions

the three quartiles with a minimum and maximum value added on

a measure of the difference between two quartiles (not necessarily consecutive)

• a box-and-whisker-diagram; a graph of a data set, consisting of a line extending from the minimum value to the maximum value, and a box with lines drawn at the first quartile, Q1; the median; and the third quartile, Q3.
• 

• a special symbol is used to identify asterisk
• the solid horizontal line extends as far as the minimum and maximum data values that are NOT outlies

68%

95%

99.7%