in combination, does order matter?
no
in permutation, does order matter?
yes
combination formula
nCr = n!/r!(n-r)!n things, taken r at a time
permutation formula
nPr = n!/(n-r)!n things, taken r at a time
circular permutation is used for ___?
to calculate the number of ways to arrange n objects around a circle
circular permutation formula
(n-1)!where n is number of objects youre trying to arrange in a circle.
what is the probability of rolling two dice and having the two numbers add to 4? approach???
0
how many ways can the letter in IDENTITY be arranged? approach?
0
what is the probability of pulling 3 spades in a deck without replacement? approach?
0
When dealing with an and/or statement, or means _____
add
When dealing with an and/or statement, and means _____
multiply
standard deviation definition
a measure of variability that describes an average distance of every score from the mean
5 steps to find standard deviation
1. find mean2. subtract the mean from each of the data set values3. square each of those values4. average these values5. square root that
standard deviation formula
sqrt((xn-xav)^2/(n)
variance
the standard deviation squared
z score
the measure of standard deviation
Union (u)
includes all data but excludes duplicate values(u)
intersection (n)
includes only data that exists in both sets
what is the middle box of a box and whisker plot
the middle 50%(interquartile range)
what is the middle line of a box and whisker plot?
the median value
what are the two end points of a box and whisker plot?
the max and min values
1 standard deviation from the mean is _____% of the data
68%
2 standard deviations from the mean is _____% of the data
95%
3 standard deviations from the mean is _____% of the data
99%
if p-value > significance level then you ______ the hypothesis
fail to reject
if p-value < significance level then you ______ the hypothesis
reject
z score is a measure of ______
standard deviation
what does a Z score of 2.5 mean?
2.5 standard deviations away from the mean
p-value
The probability level which forms basis for deciding if results are statistically significant (not due to chance).
when a question asks you to solve for the probability of "at least one", you can just do:
[1-(probability of none)]where x is how many choices you have