No

**association**: Hard to find a pattern showing a relationship between the variables. STEP 1: Make a scatterplot;**describe**the form, direction and strength of the relationship. Before doing the scatterplot you need to decide which variable is the explanatory variable and which is the response variable.Also asked, what does a scatter plot tell you?

**Scatter plots**are similar to line graphs in that they use horizontal and vertical axes to

**plot**data points. However, they have a very specific purpose.

**Scatter plots**show how much one variable is affected by another. The relationship between two variables is called their correlation .

What is a positive association?

**Positive correlation**is a

**relationship**between two variables in which both variables move in tandem. A

**positive correlation**exists when one variable decreases as the other variable decreases, or one variable increases while the other increases.

1

## What is a weak association?

**Association**(or Relationship)

**Association**(or relationship) between two variables will be described as strong,

**weak**or none; and the direction of the

**association**may be positive, negative or none. In the previous example, w increases as h increases.

2

## What is a negative association?

**Negative correlation**is a

**relationship**between two variables in which one variable increases as the other decreases, and vice versa. In statistics, a perfect

**negative correlation**is represented by the value -1.00, a 0.00 indicates no

**correlation**, and a +1.00 indicates a perfect positive

**correlation**.

3

## What is a non linear association?

A

**nonlinear relationship is**a type of**relationship**between two entities in which change in one entity**does**not correspond with constant change in the other entity. However,**nonlinear**entities can be related to each other in ways that are fairly predictable, but simply more complex than in a**linear relationship**.4

## What is an example of a scatter plot?

**Scatter Plots**. A

**Scatter**(XY)

**Plot**has points that show the relationship between two sets of data. In this

**example**, each dot shows one person's weight versus their height. (The data is plotted on the

**graph**as "Cartesian (x,y) Coordinates")

5

## Is it possible for a scatter plot to have a positive or negative association that is not linear?

When all the points on a

**scatterplot**lie on a straight line, you**have**what is called a perfect**correlation**between the two variables (see below). A**scatterplot**in which the points do**not have**a**linear**trend (either**positive or negative**) is called a zero**correlation**or a near-zero**correlation**(see below).6

## What is the linear association?

**Linear**relationships can be expressed either in a graphical format where the variable and the constant are connected via a straight line or in a mathematical format where the independent variable is multiplied by the slope coefficient, added by a constant, which determines the dependent variable.

7

## Can a scatter plot be linear?

**Scatter Plot**: Strong

**Linear**(positive correlation) Relationship. Note in the

**plot**above of the LEW3.DAT data set how a straight line comfortably fits through the data; hence a

**linear**relationship exists. The

**scatter**about the line is quite small, so there is a strong

**linear**relationship.

8

## What is the strength of a scatter plot?

If variable Y also gets bigger, the slope is

**positive**; but if variable Y gets smaller, the slope is negative. Strength refers to the degree of "scatter" in the plot. If the dots are widely spread, the relationship between variables is weak. If the dots are concentrated around a line, the relationship is**strong**.9

## What is negative association in math?

A

**negative correlation**is a**relationship**between two variables such that as the value of one variable increases, the other decreases.**Correlation**is expressed on a range from +1 to -1, known as the**correlation**coefficent.10

## What is the form of a scatter plot?

Scatterplots and The

**Form**(Shape) of a Relationship: The**form**or shape of a relationship refers to whether the relationship is straight or curved. Linear: A straight relationship is called linear, because it approximates a straight line.11

## What does correlation tell us about two variables?

The most common

**correlation**coefficient, generated by the Pearson product-moment**correlation**, may be used to measure the linear relationship between**two variables**. A value of zero indicates that there is no relationship between the**two variables**.12

## What does the value of correlation mean?

The Pearson

**correlation coefficient**, r, can take a range of**values**from +1 to -1. A**value**of 0 indicates that there is no association between the two variables. A**value**greater than 0 indicates a positive association; that is, as the**value**of one variable increases, so**does**the**value**of the other variable.13

## What is an outlier in a scatter plot?

**Scatter Plot**:

**Outlier**. An

**outlier**is defined as a data point that emanates from a different model than do the rest of the data. The data here appear to come from a linear model with a given slope and variation except for the

**outlier**which appears to have been generated from some other model.

14

## What is a negative relationship in a scatter plot?

A scatterplot is used to represent a correlation between two variables. There are two types of correlations:

**positive**and negative. Variables that are positively correlated move in the**same**direction, while variables that are negatively correlated move in opposite directions.15

## What is the definition of bivariate data?

In statistics,

**bivariate data**is**data**on each of two variables, where each value of one of the variables is paired with a value of the other variable. If the variables are quantitative, the pairs of values of these two variables are often represented as individual points in a plane using a scatter plot.16

## How do you find the least squares regression line?

**TI-84: Least Squares Regression Line (LSRL)**

- Enter your data in L1 and L2. Note: Be sure that your Stat Plot is on and indicates the Lists you are using.
- Go to [STAT] "CALC" "8: LinReg(a+bx). This is the LSRL.
- Enter L1, L2, Y1 at the end of the LSRL. [2nd] L1, [2nd] L2, [VARS] "Y-VARS" "Y1" [ENTER]
- To view, go to [Zoom] "9: ZoomStat".

17

## What is the definition of correlation in math?

Positive

**correlation**. If there is a**correlation**between two sets of data, it means they are connected in some way. We have seen that as the temperature increases, the**number**of ice-creams sold increases. The results are approximately in a straight line, with a positive gradient.18

## What is a negative linear relationship?

Scatter Plot: Strong

**Linear**(**negative**correlation)**Relationship**. The slope of the line is**negative**(small values of X correspond to large values of Y; large values of X correspond to small values of Y), so there is a**negative**co-relation (that is, a**negative**correlation) between X and Y.