Reviewer - Stats Flashcards
experiment?
activity that can be repeatedly done under similar conditions
outcome?
the result of the experiment
sample space
possible outcomes in the experiment
what is random variable?
numerical amount that results from an experiment
what are the 2 types of random variable?
- discrete
- continuous
discrete?
countable numbers
continuous
not countable but measurable
( height, weight )
non-negativity property?
between 0 to 1 or 0<p(x)<1
norming property
Σ p(x)=1
Probability Mass Function or Discrete Random Distribution
it consist of values of a random variable can assume and the corresponding probability
symbol of observation in sample & population data
n & N
symbol of mean in sample & population data
x̄ & µ
symbol of variance in sample & population data
s^2 & σ^2
symbol of SD in sample & population data
s & σ
what is variance?
describe the amount of spread, dispersion in a distribution
what is SD?
a measure of how dispered the data is
what is mean?
a measure of the central location of a random variable
normal distribution?
is a probability function that describes how the values of a variable are distributed.
properties of norm distribution
- a bell shape
- curve symmetrical at center
- mean, median mode coincide at the center
- always approaching the axis, but never touching it ( asymptotic )
- under curve is 1
population
entire group
sample
specific group
symmetric
a balance distribution of left and right where mean is approx equal to median
skewed right
uneven distrib where the mean is larger than median
skewed left
uneven distrib where the median is larger than mean
