Normal Distribution and LSRL test study guide

How do you interpret slope?

The predicted value of [RV in context] will change by [value of slope] when [EV in context] changes by 1 unit

How do you interpret y-intercept?

The predicted value of [RV in context] is [y-intercept value] when [EV in context] equals zero

How do you interpret linear?

The rate of change between [RV in context] and [EV in context] remains constant, on average

How to interpret a positive association?

On average, [RV in context] increases as [EV in context] increases

How do you interpret a negative association?

On average, [RV in context] decreases as [EV in context] increases

How do you interpret the residual?

The difference between observed [ RV in context] and predicted [RV in context] is [value of residual]

Is a positive residual overstated or understated?

understated

Is a negative residual understated or overstated?

overstated

How do you interpret standard deviation of residual (s) ?

On average, how far [predicted RV in context] is from observed

or

On average everytime you make a prediction of [RV in context] you'll be off by [value of s]

How do you interpret the correlation coefficient (r) ?

There is a strong/weak/moderate association in the positive/negative linear relationship between [RV in context] and [EV in context]

How do you interpret the coefficient of determination ( r^2) ?

(r^2 value)% of the variation in [RV in context] can be explained by LSRL of [RV in context] on [EV in context]

What letter does the standard deviation of residual stand for?

s

What letter does the correlation coefficient stand for?

r

What letter does the coefficient of determination stand for?

r^2

How do you write the equation of the LSRL?

y-hat(RV in context)= a + bx(EV in context)

How do you from the r if you are given r^2?

Take the square root of the r^2

Example:

R-sq= 66.4%

R= square root of 0.664

What is the formula for finding out the residual?

Observed value minus the Actual value

When figuring out the strength of a number, what are the numbers for the strengths?

Weak: 0-0.4

Moderate: 0.4-0.7

Strong: 0.7-1

What is the acronym for describing the distribution of something?

DOFS

What does DOFS stand for?

Direction, Outliers/Unusual features, Form, Strength

What do you need to mention when talking about direction?

positive, negative, or none

What do you need to mention when talking about form?

linear or nonlinear

What do you need to mention when talking about strength?

strong, weak, moderate