A characteristic or measure obtained by using the data values from a sample

Statistic

A characteristic or measure obtained by using all the data values from a specific population

Parameter

ymbol for population mean

M

symbol for sample mean

_

x

The median is ______________ the mean by extrememly high or extrememly low values.

affected less than

The mean is affected by _______.

extremely high or low values, called outliers, and may not be the appropriate average to use in these situations.

n a positively skewed or right-skewed distribution the "tail" is _____

O.

to the right

In a negatively skewed or left-skewed distribution the "tail" is _____

to the left

Data values are evenly distributed on both sides of the mean; the distribution is unimodal; the mean, median and mode are the same and are at the center of the distribution

Symmetric Distribution

he symbol for population standard deviation

O

the symbol for sample standard deviation

s

he symbol for sample variance

s2

he symbol for population variance

o2

When the standard deviation is large,

he more variable the data are.

Coefficient of Variation is ________________________ .

used to compare standard deviation when the units are different

Chebyshev theorem _____________ require a specific distribution.

does not

Empirical Rule _______ require a bell-shaped/symmetric distribution

bell-shaped

A student with a percentile rank of 81 would mean that the student ____________ of the students.

did better than 81%

A z-score represents __________

the number of standard deviation that a data value falls above or below the mean

An outlier is _____________ .

an extremely high or extremely low data value when compared with the rest of the data values.

A two-column chart listing the categories

and frequencies

Frequency Distributions

frequency/total

Total relative frequency=1

Relative frequency

A bar chart with the bars organized from most to least

Pareto Chart

A circle segmented based on relative frequencies as percentages.

pie chart

The set of numbers we are determining the frequency

class

smallest & largest numbers that can be included in a class

class limits

: the range of numbers that can be in a class

class width

: are used to make sure we do not overlap the class limits

class boundaries

the middle of the class

class midpoint

(largest data value - smallest value)/# classes*

*Round UP

Class width =

single value for the class

Ungrouped

range of values for the class

grouped

The sum of the frequencies up to and including that class

Cumulative frequency

describe the sample/population

desriptive statisctics

inferance about the sample or population

inferential statistics

a characteristic or attribute that can assume different variables

variable

occur by chance

random variable

are the values the variables can be

data

each individual value

data value/datum

is all the data

data set

ex: zip code

qualitative

gender, height, weight

quantitative

countable

discrete

often measurements usually a range

continuous

variables that are assoiciated with what we are trying to measure and influence our outcome

confounding variables

samples in which each subject did not have the same chance of being selected

bias sample

the 1st subject is selected than every 5th subject after that

systemic sampling

subjects are split into groups or strata and from each group are selected at random

stratified sampling

the population can naturally be classified into groups or clusters

cluster smapling

the group we leave alone

control group

the group the treatment is given

experimental group

the variable that explains our response

independent variable

the vraiable that measures the response

dependent variable

the treatment applies is unknown

blinding

subject patient only doesnt know the treatment

single blinding

subject/patient and doctor doesnt know the treatment

double blinding

the sample may not be representative of the population

suspect samples

the word average takes on different meansings (mean, median, mode)

ambiguious averages

the results can be reported in such a way that makes it appear horrific

changing the subject

the statistics may not be compared to anything and is therefore detached

detached statistics

often times studies people imply a product may benefit you in one way or another

implied connections