# 1.2 Graphical Representation of Sample Data Flashcards

What are the two main types of plots?

- Data plots

- Frequency plots

What are examples of data plots?

- Line chart (in time)
- 2D plots (in space)
- Biplot
- Scattergram

What are examples of frequency plots?

- Pie chart
- Bar chart
- Histogram
- Frequency polygon
- Frequency table

What is a discrete quantitative random variable?

When the number of its possible values is 1) infinite or 2) infinite and COUNTABLE (integers or fractions)

What is a continuous quantitative random variable?

When the number of its possible values is infinite and UNCOUNTABLE (real numbers)

What is the notation for random variables?

Capitals

What is the notation for observed values of random variables?

Small letters

What is a real number?

A real number includes irrational numbers (cannot be constructed from ratios)

Is this an example of a discrete or continuous quantitative random variable:

Counting the number of eggs a chicken lays.

Discrete quantitative random variable

Is this an example of a discrete or continuous quantitative random variable:

Counting the number of bacteria in a swamp.

Continuous quantitative random variable

Is this an example of a discrete or continuous quantitative random variable:

Weight, height, nitrogen content, speed of a car, cholesterol rate in blood

Continuous quantitative random variable

For a given random variable X, how would you illustrate the random sample of size n?

Xn

For a given random variable X, how would you illustrate the individual observation?

xn

What directs the drawing of frequency plots?

The nature of a random variable (qualitative, discrete quantitative, continuous quantitative)

What can be added up to n? What is n?

- Frequencies or counts

- n is the sample size