1- Variable Statistics Flashcards
Quantitative
Data that has a numerical value
counts, measurements
Qualitative
data that can be put into categories
characteristic data
ex; text, labels attributes
Nominal Qualitative
data that describes a characteristic
Ordinal Qualitative
data that can be ranked or ordered
Discrete Quantitative
exact values, data that can be counted
Continuous Quantitative
decimals
ex; height + weight
How to find Q1
The median of the smaller side of the median
How to find Q3
The median of the bigger side of the median
How to find SD without frequency
Add up x’s
Find average
Subtract x-average
Square them
Add them all together
Put the sum over the # of x’s and take the square root
How to find SD with frequency
Multiply x by f
Find sum of xf
Find sum of f
Find average of x
subtract x-values by average
square them
multiply f * x^2
Put fx^2 over sum of f and square root it
How to find IQR
Q3-Q1
Upper Boundary
Q3 + (1.5*IQR)
Lower Boundary
Q1 - (1.5*IQR)
Use what to find outliers?
UB + LB
Steps to find mean with grouped frequency
Find the midpoint; add the two numbers together and divide by 2
add up the frequency
multiply fm
divide the sum of fm by the sum of f
How to find the top percent
Lower limit Add the number in the set before and the number that starts the set its in; divide by 2
How to find the median of grouped frequency
find the average and that number is where the median range will be
find where that number lies in cumulative frequency
take the smallest number in that range and the largest number in the range before it and divide by 2 (L)
add up cumulative frequency before the median class and subtract from median (I)
divide by the frequency of the set it’s in (f)
multiply by number of things in the set (c)
median formula
L + (I/f *c)
r^2 = 0
No correlation
r^2 0-.25
very weak correlation
r^2 .25-.5
weak correlation
r^2 .5-.75
moderate correlation
r^2 .75-.90
strong correlation
r^2 .90-.99
very strong correlation
