Unit II Flashcards
What is a frequency distribution?
A tabular form of data collection that gives the values it takes, and now often it takes them (frequency).
True or false: frequency distributions can be used for both qualitative/ categorical data and quantitative data.
True
What is labeled on the horizontal axis and vertical axis of a bar graph / chart?
Horizontal axis: labelled with the value of the variable.
Vertical axis: labelled with the frequency of the variable ( numbers/percentage).
What do the height of the bars of a bar chart represent?
Frequency
Do the bars touch on a bar chart?
NO
What makes a bar chart categorical?
The data does NOT need to appear in any given order.
True or false: A pie chart is suitable when respondents give more than just one answer.
False
What do the slices of a pie chart represent?
The slices correspond to the frequency of each possible response; it usually represents the proportion or percentage.
What are 3 types of graphical representation of QUANTITATIVE variables?
- Stemplots/stem and leaf plots
- Histograms
- Cumulative frequency ogives
What do stemplots show?
- The shape of the data.
- The actual values in the dataset.
What are the two main steps in plotting a stem and leaf plot?
Step 1: sort the data inn either ascending or descending order.
Step 2: separate each number into Stem and leaf.
What would be the stem and leaf of 7?
Stem (tens): 0
Leaf (units): 7
What would be the stem and leaf of 10?
Stem (tens): 1
Leaf (units): 0
What would be the stem and leaf plot of 321?
Stem (tens): 32
Leaf (units): 1
What do the horizontal and vertical axes of a histogram represent?
Horizontal axis: shows a continuous range of values for the variables.
Vertical axis: shows the frequency corresponding to the different bins.
Do the vertical bins of a histogram touch?
YES
Why don’t the bars of a bar chart touch, and why do the bins of a histogram touch?
Bar graphs show a singular value per bar, therefore resulting in a break between each value (space between the bars). The histogram however, shows a continuation in each value, so where one value ends, another can start, which is why the bins are attached.
What makes a histogram ordinal?
The values shown are a continuation of each other, therefore the order in which they’re organized matters.
True or false: the variables graphed in a histogram are quantitative while the variables graphed in a bar chart are categorical/qualitative.
True
What is the difference between the stemplot and histogram?
Both graph quantitative variables but the stemplot is used for smaller datasets, while the histogram is used for larger datasets; less than 30 values - stemplot, over 30 values - histogram
What is a cumulative frequency ogive?
A type of line graph that is constructed from frequency distributions.
What are the 2 types of cumulative frequency ogive?
- Less than cumulative frequency ogive
- More than cumulative frequency ogive
What is a less than cumulative frequency ogive?
From there, you can determine how many responses or what percentage of responses are LESS than a specific value; usually begins with zero and ends with the total sample size.
What is a more than cumulative frequency ogive?
From these, you can determine how many responses or what percentage of responses are MORE then a specific value; usually begins with the total sample size, and ends with zero.
What do the horizontal and vertical axes of a cumulative frequency ogive represent?
Horizontal axis: shows a continuous range in values for the variables.
Vertical axis: shows the frequency (# or %), corresponding to the frequencies (# or %) that are less than/more than a specific value.
What does the frequency distribution of a variable give?
It gives the possible values it takes and how often frequency or percentage); frequency distributions can be used for grouped and ungrouped data.
What is a class?
[Usually the first column] which shows the value which can be included in each row of the table.
What are the class limits?
The lowest possible value that can be in included in a class (lower class limit), and the highest possible value that can be included in a class capper class limit); specifically relates to grouped frequency distribution.
What are the class boundaries?
The numbers that separate each class.
(For example, it is the same principle that carries over when you look at two parishes, and they are separated by a border)
What is the class mark?
This is the middle of each class, and it is calculated by taking the average of the class limits.
