math chapter 1 vocab

Nominal

name for everything

Ordinal

put in order

Discrete

has to be whole numbers

continuous

decimal or fractions

Descriptive Stats

descring the numbers that was used in a poll

inferential stats

stretch the truth with what the sample data told us

Statisitic

a fact we know from the data like if we pulled 15/27 people

parameter

using that data and stretching the truth

Data

numbers itself

undercover

they don’t have the option to take it

response

they lie about it

non response

they just dont want to answer

variabilty

how its spread out: lowmed/high low mean that the main part of the dots are in the low numbers in graph

Describe a distribution (list 4 things)

Shape:Symmetrial, Skewed right or left

Varabilty: Low/Med/High spread

Center: Middle vaule

Outliers

Histrogram rules

bars have to touch each other, include numbers left not right, cant see every vaule

Measures of Center for Mean and what do you have to say

Mean is equal to average, and have to say “On average the “context” is

Measure of center for median and what you have to say

Median equals the middle vaule and have to say “about 50% of the “context” is at or belows.. whatever number it is

Choosing a measure of center what do you do

Mean- you have no resistence to outliers and skew

Median- resistance to outliers and skew

if the data is left or right do you use median or mean

use median

If skewed left is the mean = < or > median

mean is < median

If skewed right is the mean > < or =

Mean > median

If data is symmetric what do you use

use the mean

What’s the sentence and what isInterquartilie range

Sentence: The middle half of the “context” has a range of # and IQR is Q3-Q1

Standard Deviation sentence and how to find it?

Sentence: The typical distance of “context” from the mean is # and how you find it is, line up all the numbers and subtract number from mean then square all of them then add them all up then divide by one number less than you square root it.

Choosing a measure of varabilty, what are the rules?

If symmetrical use SD and mean, then if its skewed use IQR and median

What is marginal %?

B/C

What is Joint %?

A/C

What is conditional %?

A/B

If the graph isn’t the same is there an association or not?

There is an association if it isn’t the same

If the graph is the same is there an association or not?

there is no association if they are the same

If you have 2 varbailes what are the names of them? and where does the important one go?

Explanatory and response variable, explanatory goes on bottom of graph

What do you say when you have to describe relationship in scatter plot?

There is a weak, negative, linear relaonship, between “context”. There was 1 outlier and a large cluster of points/Context of it.

Whats the sentence for correlation?

The linear relationship between the 2 things compared is “psoitivite and weak”

R has to be between what?

-1 and 1

True or false: Correlation doesn’t equal causation

true

what does ^y mean?

predicted number

is explantory x or y

x

What does extrapolation mena?

a point that isn’t outlier that fits in the line but doesn’t match up with the rest of the data

what is residual?

actual-predicted

what is the y-int and a

^y=b+ax B=y-int A=slope

Whats a good residual plot

when there is no pattern

what is a bad residual plot?

when is there clear pattern

When making predictions you can choose a linear model or exponetional

linear model:^y-a+bx and exponential model:^y=a-b^x