C784 Statistics Full Course Review Concepts with Complete Solutions. Lurking Variable Correct Answer Associated with the explanatory and the response variables that is not directly being studied.
Simpson's Paradox Correct Answer Occurs when a trend or result that appears in groups of data disappears when we combine the data.
Regression Analysis Correct Answer A process for estimating and analyzing the relationship between variables.
Least-Squares Regression Line Correct Answer AKA the line of best fit. y = mx + b "rise over run"
Interpolation Correct Answer Using existing data along with the Least-Squares Regression Line to make a prediction.
Extrapolation Correct Answer Estimation by projecting OUTSIDE known data points.
p-value Correct Answer the probability that a result occurred by chance
Significance Levels in Hypothesis Testing Correct Answer Statistically Significant: If a measured p-value is less than the significance level.
NOT Statistically Significant: If a measured p-value is MORE than the significance level.
Empirical Rule Correct Answer 68 - 95 - 99.7
68% is w/in 1 standard deviation of the mean
95% is w/in 1 standard deviation of the mean
99.7% is w/in 1 standard deviation of the mean
Used for Categorical (Qual) Data Correct Answer Bar Chart
Pie Chart
Mean Correct Answer Average - adding series then dividing by the total number in that series Center & Spread Measures Correct Answer SYMMETRIC - Mean (center) / Standard Deviation (spread)
SKEWED - Median (center) / IQR (spread)
CATEGORICAL - Mode (center) / no spread
What is the difference between a bar chart and a histogram? Correct Answer BAR CHART - Categorical data distributed over groups of categories
HISTOGRAM - Quantitative data distributed over various intervals
Outlier Formula Correct Answer 1.5 x IQR above Q3 or below Q1
Graphical Displays for Quantitative Variables Correct Answer HISTOGRAMS - large data sets
STEM PLOTS - keeps individual data points DOT PLOTS - smaller data sets
BOX PLOTS - center, spread and 5 number summary
SCATTER PLOTS - x,y axis
5 Number Summary Correct Answer Min - Q1 - Median - Q3 - Max
Graphical Displays and Corresponding Numerical Analysis Tools for Examining Data Relationships Correct Answer C > C - Two-way Frequency Tables (aka Contingency Table) use conditional percentages and relative frequencies
C > Q - Side-by-Side Boxplots use 5 number summaries
Q > Q - Scatterplots use correlation coefficients
InterQuartile Range (IQR) Correct Answer Q3-Q1
Standard Deviation Correct Answer Average distance each data point is from the mean
3 Types of Percentages on a Two-Way Frequency Table Correct Answer OVERALL% - (aka Relative Frequencies) When all of the counts are divided by the overall total
CONDITIONAL ROW% - when the explanatory variable is in rows; calculated by dividing the joint frequencies of each row by the row total
CONDITIONAL COLUMN% - when the explanatory variable is in the columns; calculated by dividing joint frequencies of each column by column total
Right and Left Skew Correct Answer Right Skewed is positive (tail li.)
Simpson's Paradox Correct Answer Occurs when a trend or result that appears in groups of data disappears when we combine the data.
Regression Analysis Correct Answer A process for estimating and analyzing the relationship between variables.
Least-Squares Regression Line Correct Answer AKA the line of best fit. y = mx + b "rise over run"
Interpolation Correct Answer Using existing data along with the Least-Squares Regression Line to make a prediction.
Extrapolation Correct Answer Estimation by projecting OUTSIDE known data points.
p-value Correct Answer the probability that a result occurred by chance
Significance Levels in Hypothesis Testing Correct Answer Statistically Significant: If a measured p-value is less than the significance level.
NOT Statistically Significant: If a measured p-value is MORE than the significance level.
Empirical Rule Correct Answer 68 - 95 - 99.7
68% is w/in 1 standard deviation of the mean
95% is w/in 1 standard deviation of the mean
99.7% is w/in 1 standard deviation of the mean
Used for Categorical (Qual) Data Correct Answer Bar Chart
Pie Chart
Mean Correct Answer Average - adding series then dividing by the total number in that series Center & Spread Measures Correct Answer SYMMETRIC - Mean (center) / Standard Deviation (spread)
SKEWED - Median (center) / IQR (spread)
CATEGORICAL - Mode (center) / no spread
What is the difference between a bar chart and a histogram? Correct Answer BAR CHART - Categorical data distributed over groups of categories
HISTOGRAM - Quantitative data distributed over various intervals
Outlier Formula Correct Answer 1.5 x IQR above Q3 or below Q1
Graphical Displays for Quantitative Variables Correct Answer HISTOGRAMS - large data sets
STEM PLOTS - keeps individual data points DOT PLOTS - smaller data sets
BOX PLOTS - center, spread and 5 number summary
SCATTER PLOTS - x,y axis
5 Number Summary Correct Answer Min - Q1 - Median - Q3 - Max
Graphical Displays and Corresponding Numerical Analysis Tools for Examining Data Relationships Correct Answer C > C - Two-way Frequency Tables (aka Contingency Table) use conditional percentages and relative frequencies
C > Q - Side-by-Side Boxplots use 5 number summaries
Q > Q - Scatterplots use correlation coefficients
InterQuartile Range (IQR) Correct Answer Q3-Q1
Standard Deviation Correct Answer Average distance each data point is from the mean
3 Types of Percentages on a Two-Way Frequency Table Correct Answer OVERALL% - (aka Relative Frequencies) When all of the counts are divided by the overall total
CONDITIONAL ROW% - when the explanatory variable is in rows; calculated by dividing the joint frequencies of each row by the row total
CONDITIONAL COLUMN% - when the explanatory variable is in the columns; calculated by dividing joint frequencies of each column by column total
Right and Left Skew Correct Answer Right Skewed is positive (tail li.)
