Regression
What type of regression quantifies the relationship between the dependent and a single explanatory variable
Simple Linear Regression
What bases it's forecasts on a weighted average of past observations, with more weight on the more recent observations?
Exponential smoothing
What is the single most important distribution in statistics
Normal distribution
_____ includes all members of the group we want to study.
Ex. registered voters in the U.S.
All customers that shopped at Publix stores in 2019
What is Population?
What are the two possible outcomes for hypothesis testing?
Fail to reject the null and Reject the null
___ is the dependent variable, and ___ is the explanatory (independent) variable
Y, X
What method of exponential smoothing is appropriate for a series with seasonality (and possibly trend)?
Winter's Method
What is the number of standard deviations X is to the right or left of the mean?
Z-Value
_____ variable: describes a measurable quantity _____ variable: describes a quality of a population member
What is Numerical & Categorical
Type 1 error
What summarizes all residuals. Basically the standard deviation of the residuals
What is the standard error of estimate?
Moving average models
What is the formula for confidence intervals?
Confidence interval=sample mean+/- margin of error
Ex. Gender: 1 for male, 0 otherwise
Coding
What describes the percentage of variation of the dependent variable explained by the regression?
R^2
What quantitative method of testing is used for randomness? The null hypothesis is that the data are random.
Runs Test
True/False: The mean of a sampling distribution of x-bar is the same as the mean of the population distribution μ
True
What are the best ways to visualize categorical variables and numerical variables?
Categorical: Column Charts & Pie Charts
Numerical: Histograms & Boxplots
When would we use a difference in means test?
when there are two independent samples
What explanatory variables other than basic numerical variables can be included in regression equations?
Dummy variables and Interaction variables
What is the the difference between linear trends and exponential trends?
Linear trends change by a constant amount each each time while exponential trends change by a constant percentage.
What is a statistic which when calculated as part of a confidence interval gives the probability that the interval will capture the true parameter value in repeated samples?
Confidence Level
Approximately what percent of observations are within two standard deviations of the mean?
95%
What type of test is used for hypothesis tests concerning the variance of a normally distributed population?
What is the Chi-Squared Test