Exam II Lecture 10 Stats 1 Flashcards
Difference between population and sample.
Population includes all of the individuals being studied.’
Samples are a subcollection of members selected from the population.
Dependent variable vs independent variable
Influenced by another factor, it is what you are trying to measure.
The independent variable influences the dependent factor
Parameter vs statistic
PAramaters are mathematical descriptions of a population characteristic.
Statistics are a mathematical description of a sample characteristic.
Descriptive statistics
Summarize and describe the characteristics of data numerically and graphically
categorical data
names, labels etc.
Categorical data.
Quantitiative data
consists of numbers representing measurements.
Further broken into discrete and continuous measurements.
Discrete data
A type of quantataive data where the numbers are finit/countable.
Ex: Number of eggs a hen lays or people admitted to ER.
Continuous data
A type of quantatative data in which the result is infinitely possible.
Nominal measurement
data consiting of names, labels, or categories.
LEAST PRECISE LEVEL OF MEASUREMENT.
Ordinal level of measurement
Data that can be put into some sort of order. but the dfferences between data values is not meaningful.
example race placement.
Interval level of measurement
Much like ordinal level in that they can be paced in order but there is no COMMON STARTING POINT OR ZERO POINT.
Example is temeprature scale or sea level.
The most precise scale of measurement
Ratio level
Interval level with additional property that there is also a natural zero starting point.
Examples: Height, weight, price of college text books.
Observational study
Observing and measuring specific characteristics without attempting to modify the subjects being studied.
NO MANIPULATION OF SUBJECTS.
Experimental study
Apply some treatment and then observe its effects on the subjects.
Relative frequency distribution
Class frequency / Sum of all frequencies.
to make it a percentage frequency, just multiply by 100%
Ogive graph
A line graph that depicts cumaltive frequncies.
Bar graph
Uses bar to depict QUALITATIVE VARIABLES
Vertical scale is values horizontal scale is the different categories of qualitative variables.
Linear correlation coeficient
Known as r
Or PEarson correlation coeficient
Measures the strength of the linear relationship between the paired quantitative X and Y values within the sample.
If R=0 there is no correlation.
Describe the itnerpretation of R (linear correlation coeficient)
the absolute value of r indicates strength of the relationship.
r is not affected by choice of x and y.
r is very sensitive to outliers.
Describe the strength of r the linear correlation coeficient.
.8-1 very strong. .6 - 8 strong .4 to .6 moderate .2 to .4 weak .0 to .2 wear or no relationship.
