Descriptive Statistics
- Four Scales of Measurement:
- Nominal: Data is categorized into distinct groups with no specific order. Examples include gender, ethnicity, and eye color.
- Ordinal: Data can be ranked or ordered, but the differences between values are not consistent or meaningful. Example: Education levels (e.g., high school, college, postgraduate).
- Interval: Data is measured on a scale where the differences between values are consistent, but there is no true zero point. Example: Temperature in Celsius or Fahrenheit.
- Ratio: Data has a true zero point, and both the differences between values and ratios of values are meaningful. Examples: Height, weight, age, income.
- Organization and Presentation of Data:
- Charts and Graphs: Visual representations of data to show patterns, trends, and relationships.
- Frequency Distribution Terms:
- Frequency: The number of times a particular value occurs in a dataset.
- Relative Frequency: The proportion of times a value occurs relative to the total number of data points.
- Cumulative Frequency: The sum of frequencies up to a certain value.
- Cumulative Relative Frequency: The sum of relative frequencies up to a certain value.
- Frequency Table and Histogram:
- Frequency Table: A table showing the distribution of data values and their corresponding frequencies.
- Histogram: A graphical representation of data using bars to show the frequency of values in different intervals.
- Frequency Polygons and Frequency Curves:
- Frequency Polygon: A graph created by connecting the midpoints of the tops of histogram bars with straight lines, representing the frequency distribution.
- Frequency Curve: A smooth curve that represents the frequency distribution of a large dataset, often resembling a bell-shaped curve (normal distribution).
- Types of Frequency Curves:
- Normal Distribution: A bell-shaped curve where data is symmetrically distributed around the mean.
- Positively Skewed (Right Skewed): The tail of the curve extends towards higher values.
- Negatively Skewed (Left Skewed): The tail of the curve extends towards lower values.
- Bimodal Distribution: Two distinct peaks in the frequency curve.
- Uniform Distribution: All values have approximately the same frequency.
[mediator_tech]
Evaluation
1. Nominal scale categorizes data into distinct groups with no specific _________.
a) Magnitude
b) Order
c) Range
2. Ordinal scale allows data to be __________ or ordered.
a) Randomized
b) Ranked
c) Counted
3. Interval scale has consistent differences between values but lacks a true _________ point.
a) Peak
b) Zero
c) Median
4. Ratio scale has both meaningful differences and ratios of values due to a true _________ point.
a) Maximum
b) Zero
c) Median
5. Charts and graphs visually represent data to show patterns and _________.
a) Summaries
b) Relationships
c) Averages
6. Frequency is the number of times a specific value appears in a _________.
a) List
b) Dataset
c) Category
7. Relative frequency is the proportion of times a value occurs relative to the total number of _________.
a) Variables
b) Data points
c) Charts
8. Cumulative frequency is the sum of frequencies up to a certain _________.
a) Average
b) Value
c) Interval
9. Cumulative relative frequency is the sum of relative frequencies up to a certain _________.
a) Data point
b) Pattern
c) Category
10. A histogram uses bars to represent the _________ of values in different intervals.
a) Frequency
b) Mean
c) Median
11. A frequency polygon is created by connecting the midpoints of the tops of _________ bars.
a) Line
b) Pie
c) Histogram
12. A frequency curve is a smooth representation of data that often resembles a _________ curve.
a) Linear
b) Circular
c) Bell-shaped
13. Normal distribution is a bell-shaped curve where data is symmetrically distributed around the _________.
a) Maximum
b) Mean
c) Median
14. Positively skewed curves have tails extending towards _________ values.
a) Lower
b) Higher
c) Median
15. A bimodal distribution shows _________ distinct peaks in the frequency curve.
a) Three
b) Two
c) Many