# 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