AP Statistics Exam Review

What is a dotplot? - Answer- A graphical display which shows "dots" for each point. It's good for categorical data- ie data classified into categories. What's the difference between categorical and quantitative data? - Answer- Categorical data fits into various categories; whereas, quantitative data has numerical values associated with it. What is a bar chart? - Answer- A display for categorical data which indicates frequencies or percents for each category. What are histograms? - Answer- Histograms are good for large quantitative data sets- either having numbers at the left/right of a bar to show the amount of data in-between each value or in the center of a bar to show the amount of data at a certain value. Sometimes, the axis will just be the frequency, but often, it can be the relative frequency (ie. amount/total). What do relative areas in histograms mean? - Answer- Relative areas correspond to relative frequencies (ie. if 10% of the area for a histogram is between 25-26, that means that 10% of the data falls between 25 and 26. What's a stemplot/stem and leaf plot? - Answer- It has stems which are some digit and leaves which are the other part of the number (for example depending on context 5|7 could be 57, 5.7, or some other variant- that's why a key must always be included). It's good for looking at individual data in small data sets. What is important in analyzing visual data displays? - Answer- SOCS (Shape, Outlier, Center, Spread): Shape-How is the data shaped (skewed left/right, symmetric, bimodal, etc.)? Are there any clusters (subgroups which the data falls into)? Are there any gaps in the data set? Outliers: Are there any outliers within the data set? Center: Give the mean/median- the value which is the approximate midpoint of the data Spread- What is the range OR IQR (if it's easy to find) of the data set? What is a mode? How do modes relate to unimodal/bimodal data sets? - Answer- A mode is a major peak in the data (most repeated value). A unimodal data set has just one mode; whereas, a bimodal data set has two modes. What are some possible descriptions of shapes within distributions? - Answer- Symmetric- There is a vertical line of symmetry, splitting the graph into two equal parts. Skewed Right- Data decreases for higher values/has less area for higher values