STATS 1

• collection of persons, items, or interests
• "all automobiles"

Where researches gather data from whole populatin for a given measurement of interest

portion of the whole and if properly take, is rep of the whole

business analyst is usin data gathered on a group to describe or reach conclusions about that same group.

researhers gather data from a sample and uses the stats generated to reach conclusion about the population from which the sample was taken

descriptive measure of the population.Greek letters

• lowest level of measurement
• representing nominal level data used to classify or categorize

measure is higher than nominal. RANK

measure next to the higest level of data in which the distancecs between consecutive numbers have meaning and the data are always numerical.

• highest level.
• height, weight, time, volume

require data to be interval or ration.

analyze interval or ratio data.

Raw data, or date that have not been summarized in any way

data been organized into a frequency distribution.

summary of data presented in the form of class intervals and frequencies.

difference between the largest and smallest number

• midpont of each class interval
• halfway acoss the class interval and be calculated as the average of the class endpoints.

• proportion of the total frequency that isw any given class interval in a frequency distribution.
• Individul class frequency divided by the total frequency.

a running total of grequencies through the classes of a frequency distribution.

is a series of contiguous bars or rectangles that rep the frequency of data given class intervals.

ploted as a dot at the class idpoint and the dots are connected by a series of line segments.

cumulative frequency polygon

display continuous , quatative data/

seperating the digits are the stem and consist of the higher value digits

a circular depiction of data where the area of the whole pie represents 100% of the data and slices of the pie represent and a percentage breakdown of the sublevels.

bars

use this tally to produce a vertical bar chart that displays the most common tyesps of defects, ranked in order of occurence from left to right.

two dimesional graph plot of pairs of points from numerical variables

yield info about the center, middle part or group of numbers

the most frequently occuring value in a set

the case of a tie for most frequently, occurring number.

Data sets with more than two modes

the average of a groupe of numbersand is computed by summing all numbers and dividing the number of numbers.

describe the spread of the dispersion of a set data.Using measures of varability in conjunction with measures of central tendency makes possible a more complete numerical description of the data

• range of values between the first and third quartile.
• q3-q1`

subtracting the mean from each value of data yields

average of the absolute values of the deviations around the mean for a set numbers

average of the squared deviations about the arthmetic mean for a set of numbers.

sum of the squared deviations about the mean of a set of values

square root of variance

Chebyshevs theorem

is computed by summing the data values and dividing the number of values

distribution is asymmetrical or lacks symmetry

describe the amount of peakedness of a distribution.

distributions that are thin and high

distributions that are flat and spread out

normal

diagram that utilizes the upper and lower quartiles along with the median and the two most extreme values to depict a distribution graphically.

determined prior to the experiment

a process that produces outcomes, and an event, which is an outcomes of an experiment.

the probablity of an event occuring is equal to the number of times the ven has occurred in the past divided by the total number of opportunites for the event have occurred

assigning probality based onm the feelings inisghts determing the probablity

a process that produces outcomes

outcome of an experiment

events that cannot be decomposed or broken down

contains the elements common to both sets

occurrence or nonoccurrence of one of the events does not affect the occurrence or nonoccurrence of the other event

elementary events of an experiment not in A comprise its complement

marginal, union, joint, and conditional