2nd A.T rev. Flashcards
What are the two types of data analysis?
- descriptive
- inferential
The measures of central tendency is under what type of data analysis?
descriptive analysis
True or false: Central tendency is useful, but it fails to account for the general distribution of data.
True
Complete the statement.
The measure of central tendency of a distribution summarizes the data set…
into a single figure representing the data set
What do measures of dispersion describe?
How similar the data are in a set.
What is another term for measures of dispersion?
measures of variability
How is the dispersion of data related to the homogeneity of data?
- more similar data = lower dispersion
- less similar data = higher dispersion
What are the three measures of central tendency?
- mean
- median
- mode
Explain the two types of data.
- ungrouped data (raw data)
- grouped data (presented in tables)
Through which table are data usually turned into grouped data?
frequency table
What is a mode?
It is the most frequent item in your data set.
A data set may be unimodal, bimodal, trimodal, or have no mode at all.
What is a mean?
It’s the sum of all values divided by the total number of values.
What is a median?
It is the middle number in an ordered dataset.
Identify the given symbol or variable. | Mode or Median
N or n
total number of values under frequency
Identify the given symbol or variable. | Mode or Median
C
group width
Identify the given symbol or variable. | Mode or Median
L or Lmd
lowest boundary of the modal or median class
Identify the given symbol or variable. | Mode or Median
f or fmd
frequency of the modal or median group
Identify the given symbol or variable. | Mode or Median
F or fmd-1
cumulative frequency of groups before modal or median group
Identify the given symbol or variable. | Mean
x̄
Ungrouped
sample mean
Identify the given symbol or variable. | Mean
Σxi
Ungrouped
summation of the items in the data set
Identify the given symbol or variable. | Mean
n
Ungrouped
number of items in the data set
Identify the given symbol or variable. | Mean
x
Grouped
average of the class boundaries
What is the formula when finding the mean for ungrouped data?
x̄ = (Σxi/n)
What is the formula when finding the mean for grouped data?
x̄ = (Σf*x)/n
What is range?
- Ungrouped data: It is the difference between the largest and smallest values in a data set
- Grouped data: It is the difference between the upper boundary of the highest class interval and the lower boundary of the smallest class
What does MAD stand for?
Mean Absolute Deviation
What does the mean absolute deviation (MAD) measure?
The average distance of each observation away from the mean of the data.
How is the formula for the ungrouped data’s MAD different from that of the grouped data’s?
Instead of the absolute value of the difference between the raw data and sample mean, the summation of the frequency multiplied to the aforementioned variables is executed.
What is a standard deviation?
It measures the average deviation of observations from the mean, and it is the most common measure of disperson used in research.
In statistics, which type of standard deviation is commonly used?
s for sample
What is the formula for finding the standard deviation in ungrouped data?
- n>30 has s = √(Σ(xi-x̄)^2)/n)))
- n<30 = √(Σ(xi-x̄)^2)/n-1)))
What is variance?
It is the square of the standard deviation (s^2).
The data can only be categorized.
Nominal Level
The data can be categorized and ranked
Ordinal Level
The data can be categorized, ranked, and evenly spaced
Interval Level
The data can be categorized, ranked, evenly spaced, and has a natural zero
Ratio Level
You can categorize your data by labelling them in mutually exclusive groups, but there is no order between the categories.
Nominal Level
Identify which level of measurement should be used given the idea below.
ethnicity
nominal
Identify which level of measurement should be used given the idea below.
car brands
nominal
Identify which level of measurement should be used given the idea below.
gender
nominal
Identify which level of measurement should be used given the idea below.
marital status
nominal
You can categorize and rank your data in an order, but you cannot say anything about the intervals between the rankings.
Ordinal Level
Identify which level of measurement should be used given the idea below.
top 3 medallists in a race
ordinal
Identify which level of measurement should be used given the idea below.
level of an ability
ordinal
Identify which level of measurement should be used given the idea below.
Likert-type questions
(least likely to most likely)
ordinal
Identify which level of measurement should be used given the idea below.
personality inventories
interval
You can categorize, rank, and infer equal intervals between neighboring data points, but there is no true zero point.
Interval Level
Identify which level of measurement should be used given the idea below.
test scores
interval
A zero on a test is arbitrary; it does not mean that the test-taker has an absolute lack of the trait being measured.
Identify which level of measurement should be used given the idea below.
temperature
interval
Zero degrees is defined differently depending on the scale – it doesn’t mean an absolute absence of temperature.
You can categorize, rank, and infer equal intervals between neighboring data points, and there is a true zero point.
Ratio Level
Identify which level of measurement should be used given the idea below.
weight
ratio
Identify which level of measurement should be used given the idea below.
temperature in Kelvin
ratio
Identify which level of measurement should be used given the idea below.
age
ratio
Identify which level of measurement should be used given the idea below.
height
ratio
