Probability
A fair 6 sided dice is rolled. What is the probability of rolling an even number?
3/6 or 1/2
What is statistical interference?
Process of drawing conclusions or making predictions about a population based on sample data?
What is the purpose of regression analysis in statistics?
Examine the relationship between a dependent and independent variable
What is the difference between a sample and a population?
Population: Entire group of individuals or subjects
Sample: Subset of that population that you collect data from
What is included in the 5 number summary?
4/52 or 1/13
What is the purpose of hypothesis testing in statistical interference?
Allows us to make decisions and draw conclusions about population parameters based on sample data
How do you interpret the slope in a regression equation?
What is stratified sampling?
Population is divided into subgroups based on shared characteristics and then a selection is made from each group
What does a smaller IQR indicate?
The data is more tightly clustered around the median
A bag contains 4 red marbles and 6 marbles. You randomly select 3 without replacement. What is the probability that all 3 marbles are blue?
1/6
How do you determine if a result is statistically significant?
We use p-values to determine the significance of a result. If the p-value is below a certain threshold (often 0.05) we consider the result statistically significant
What is R squared in regression analysis?
Represents the proportion of the variation in the dependent variable that can be explained by the independent variables. Ranges from 0-1
What is convenience sampling?
Selecting individuals who are readily available and easy accessible
Name a way you can compare the IQR's of two data sets?
Boxplot etc.
3/8
What is the difference between type 1 and type 2 errors?
Type 1: Reject a true null hypothesis
Type 2: Occurs when we fail to reject a null hypothesis
How do you test the significance of the slope in a regression model?
Using a t test
What is cluster sampling?
Dividing population into groups and random selecting entire clusters to be included in the sample
What does a large IQR indicate?
The data set is spread out widely
A bag contains 5 red marbles and 3 blue marbles. You randomly select 2 marbles without replacement. What is the probability that both marbles are red?
5/14
How do you deal with outliers in statistical analysis?
Determine if they are due to errors or represent genuine data points. May choose to remove outliers, transform and data.
What is the difference between simple linear regression and multiple?
Simple: One dependent variable
Multiple: One independent and multiple independent variables
What are advantages of cluster sampling?
Time saving, cost effective, and practicality
How to identify outliers?
1.5 x IQR rule