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25 Cards in this Set
 Front
 Back
State the 689599.7 rule.

The 689599.7 rule describes what percent of observations lie within one, two ,and three standard deviations of the mean.


What are the three assumptions for fitting a regression line?

assumption of linearity
assumption of independence assumption of constant variant 

Name four types of graphs you might use to represent quantitative data.

stem and leaf plot
dot plot histogram box and whisker plot 

Define categorical data

It describes different groups for the variable.


Name the four properties of the normal distribution density curves.

follow empirical rule(689599.7 rule)
has a total area of 1.0 be above horizontal axis it's symmetric around the mean. 

What do we do with suspected outliers?

observe
see if it is influential check if it is a valid part of the study. 

Define simple random sample (SRS).

A portion of population where every individual has an equal chance of being selected.


What numerical measures of central tendency and dispersion best describe a symmetric distribution?

X and S for sample and ä and ì for population.


When we write the least squares regression line, the slope and yintercept are found by minimizing the sum of squared distances between what two values?

The observed and the predicted.


What does R square measure?

It measures the reduction of variability in the response variable.


Define a statistic.

It is calculated from a sample of a population and estimates a parameter.


Define a discrete quantitative variable.

A variable set that has gap between the values the variable may assume.


What does the sample correlation coefficient measure?

It measures the strenght and direction of a linear relationship denoted.


What numerical measures of central tendency and dispersion best describe a distribution that is skewed or has outliers?

Five number summaries.


Define a parameter.

It defines numerically the center and/or spread of a population's distribution.


Define quantitative data.

It describes a quantity or numeric value for the variable for which adding and averaging make sense.


Define a continuous quantitative variable.

A set of variable that does not have gaps between the values the variable may assume.


Define bias.

It is when one response is systematically favored over another.


If you wanted to predict Y, for what range of X values would you feel confident using your regression equation to do so?

The range of x of what you study.


What do residuals measure?

Residuals measure the difference between an observed value of the reponse and the value predicted by the regression line.


What is the first step in fitting a linear regression equation?

I don't know


Name two types of graphs you might use to represent categorical data.

pie chart
bar chart 

What is the first step in data analysis?

The first step is to make a graph.


What is a lurking variable?

They are variable that have an effect on the response but have not been measured.


Define population.

Entire collection of individual of interest.
