Chapter 1 section 1-3 Flashcards
What is statistics? And what is the goal of Statistics?
is the art of collecting, organizing, and describing data, and making inferences based on the data.
What is aim of the language of statistics?
is to draw conclusions about the real world based on observations one makes. The idea is to take draw conclusions about a population from a sample taken from that population.
What is natural variability in data? And does it always exist in data?
Natural variability in data refers fluctuations in data that occur as a result of natural, inherent and n-various uncontrolled factors. THERE WILL Always be NV in Data.
What are extraneous factors in the context of data and statistics?
refer to any external factors that affect the outcome, other than the intended treatment.
What are the two sections of statistics?
- descriptive: one is simply describing the observed sample
- inferential: using info found in a sample to draw conclusions about the general population.
Define the following words, and include their symbols?
1. Population:
2. Sample:
3. Well Representative sample:
- the complete set of units we are interested in studying. These units could be people, animals, places, etc. AKA target population.
SYMBOL: N= population size - a subset or segment of a population.
Sample size: n - the sample well represents the overall population and shares the same characteristics. (Our goal is to always have a well-represented sample)
What is a parameter and what is it attributed to?
Give an example:
is the specific aspect of a population that you want to study.
EX:
Population: All students at a University.
Parameter: The average GPA of all students at a university.
What is a statistic and what is it used for?
a numerical value calculated from a sample and varied from one sample to another.
We use statistics to draw conclusions about the parameter.
What is a random variable and the types of Random variables:
variable that can’t be predicted in advance.
Qualitative and Quantitative RV.
What are types of Quantitative RVs?
Discrete: RVs that assume specific values only
Continuous: RVs that can assume a range.
What is a frequency distribution, what is it used for, and its notation?
is a table used to represent quantitative data, whether it is discrete or continuous. Where:
X= Unique data values
f(x)= frequency of the data.
What is a relative Frequence distribution, and what is it used for?
table that lists data values and their frequency in percentages.
What do we use to quantify uncertainty in data?
probability:
What do we calculate probability in, a parameter or a statistic?
we calculate probability in a statistic as it is a changing variable. We can’t calculate the probably of a constant as it going to be either 0 or 1, it is either going to happen or not. Thus, when we calculate probability, it is in relation to the statistic not the parameter.
What are the symbols for the following in stats:
1. Sample:
2. Population:
- n
- N
