Stats 101 Exam Short Answers Flashcards
What are the 3 Assumptions for Two Independent Sample T-Procedures?
Observations from within same group and between groups are independent, underlying distributions are normal.
What are the 2 Forms of the Two Independent Sample T-Test?
Pooled and non-pooled forms.
What is the Pooled Form of the Two Independent Sample T-Test?
Carries the assumption of equal standard deviations.
What is the Non-Pooled Form of the Two Independent Sample T-Test?
Doesn’t carry the assumption of equal standard deviations.
What are the 2 Assumptions for One Sample T-Procedures?
Observations are independent of each other, underlying distribution is normal.
What Happens for One Sample T-Tests if the Sample Size is Large?
We don’t need the normality assumption.
How do we Calculate the F-Test Statistic?
Divide variability between group means by the variability within the groups.
What are the 4 Assumptions for One-Way ANOVA F-Tests?
Observations from within groups are independent, groups are independent, underlying distributions are normal, standard deviations are equal.
How do we Check Standard Deviations are Equal?
Largest se / smallest se should be < 2.
How do we Calculate the Chi-Square Test Statistic?
(Observed count - expected count)^2 / expected count for each cell added together.
What are the Two Requirements for the Chi-Square Test Statistic?
At least 80% of the expected counts must be 5 or more, each expected count must be greater than 1.
What is B0?
The y-intercept.
What is B1?
The slope of the line (infront of the x).
What does r Measure?
The strength and direction of the linear association between two numeric variables, how close the points come to lying on a straight line.
Does r Have Units?
No.
What is r?
Sample correlation coefficient.
What can the Values of r be?
-1 to 1.
What is Linearity?
The relationship between x and the mean value of Y at X = x is linear.
What is Normality?
The random errors are normally distributed with mean zero.
What is Constant Spread?
The random errors all have the same standard deviation regardless of the value of x.
What is Independence?
The random errors are all independent.
