Data Analysis Exam 2

Type I Error

rejected the null hypothesis, when in reality the null hypothesis was true

Type II Error

Failed to reject the null hypothesis when in reality the null hypothesis was false

Correlation:

measures the degree of a linear relationship between two variables

When dealing with categorical data in a regression you must use…

a dummy variable (assigning numerical value to category i.e. 0 or 1)

If p-value is greater than alpha,

assume equal variances

If the p-value is less than alpha,

assume unequal variances

Single factor(One way) ANOVA

Use it when we have 3 or more groups

In a Single Factor (One Way) Anova

Null hypothesis means equal

Alt Hypothesis the means of at least two of the groups differ

If P-value is less than alpha

REJECT THE NULL HYPOTHESIS!!!!

R-square explains…

percent of the variability in y explained by the model’s predictors.

The p-value measures

the probability of obtaining the observed results assuming the null hypothesis is true.