Statistics: Introduction
Population vs Sample
The population includes all objects of interest whereas the sample is only a
portion of the population. Parameters are associated with populations and
statistics with samples. Parameters are usually denoted us
Stats: Measures of Variation
Range
The range is the simplest measure of variation to find. It is simply the highest
value minus the lowest value.
RANGE = MAXIMUM - MINIMUM
Since the range only uses the largest and smallest values, it is greatly affected
b
Stats: Measures of Central Tendency
The term "Average" is vague
Average could mean one of four things. The arithmetic mean, the median,
midrange, or mode. For this reason, it is better to specify which average you're
talking about.
Mean
This is what peopl
Statistics: Grouped Frequency Distributions
Guidelines for classes
1. There should be between 5 and 20 classes.
2. The class width should be an odd number. This will guarantee that the
class midpoints are integers instead of decimals.
3. The classes must
Stats: Measures of Position
Standard Scores (z-scores)
The standard score is obtained by subtracting the mean and dividing the
difference by the standard deviation. The symbol is z, which is why it's also
called a z-score.
The mean of the standard scores
Stats: Counting Techniques
Fundamental Theorems
Arithmetic
Every integer greater than one is either prime or can be expressed as an unique
product of prime numbers
Algebra
Every polynomial function on one variable of degree n > 0 has at least one real
or
Stats: Binomial Probabilities
Binomial Experiment
A binomial experiment is an experiment which satisfies these four conditions
A fixed number of trials
Each trial is independent of the others
There are only two outcomes
The probability of each outcome rem
Stats: Probability Distributions
Probability Functions
A probability function is a function which assigns probabilities to the values of
a random variable.
All the probabilities must be between 0 and 1 inclusive
The sum of the probabilities of the outcome
Stats: Conditional Probability
Conditional Probability
Recall that the probability of an event occurring given that another event has
already occurred is called a conditional probability.
The probability that event B occurs, given that event A has already
Stats: Introduction to Probability
Sample Spaces
A sample space is the set of all possible outcomes. However, some sample
spaces are better than others.
Consider the experiment of flipping two coins. It is possible to get 0 heads, 1
head, or 2 heads. Thus
Intro to statistics I class notes 1/14/13
Chapter 1 Statistics Success Stories and Cautionary Tales
1.1- What is statistics?
1.1.1. Statistics: Numerical facts. Example: Advertisements, sport stats, unemployment
rate, approval rating. OR Statistics: a col