Calculate Variance and Standard Deviation

A confidence interval gives an estimated range of values which is likely to include an unknown population parameter.

In the context of multiple linear regression, we often compute confidence intervals for the coefficients of the independent variables.

It means we would be 95% confident that the true population effect of 'Car Age' on 'Sale Price' is between -$700 and -$300.

<p>The significance level, often denoted as alpha, determines the threshold below which we reject or accept a null hypothesis in hypothesis testing.</p> Signup and view all the answers

<p>The p-value represents the probability of obtaining results as extreme as the observed data, assuming the null hypothesis is true.</p> Signup and view all the answers

<p>A nominal variable is a categorical variable without a natural ordering of its levels.</p> Signup and view all the answers

<p>An ordinal variable is a categorical variable with levels that have a natural ordering.</p> Signup and view all the answers

<p>The main difference is that ordinal variables have levels with a natural order, while nominal variables do not.</p> Signup and view all the answers

<p>Selection bias occurs when non-random selection of participants leads to a non-representative sample.</p> Signup and view all the answers

<p>Sampling bias causes results to be skewed due to the sample not being representative of the entire population.</p> Signup and view all the answers

<p>Addressing these biases ensures that research findings are more reliable and generalizable.</p> Signup and view all the answers

<p>The median_edu variable represents the median education level in a county, categorized as below_hs, hs_diploma, some_college, or bachelors.</p> Signup and view all the answers

<p>To simplify analyses, nominal variables are treated as unordered to avoid assumptions of natural ordering.</p> Signup and view all the answers

<p>Ordinal variables provide additional information due to their ordered levels, allowing for comparisons based on the natural hierarchy.</p> Signup and view all the answers

<p>Understanding variable types helps in choosing appropriate analytical methods and interpreting results accurately.</p> Signup and view all the answers