Probability and Statistics Flashcards
What is one easy way to solve permutations?
Fundamental Counting Principle
What is an ordering of n objects?
Permutations
What does n! mean?
n times all the whole numbers less than it.
What is n! called?
n factorial
How is the number of permutations of r object taken from a group of n distinct objects denoted?
nPr
What is the formula for nPr?
n! / (n-r)!
What is a selection of object from a group, where order is NOT important?
Combination
What does n stand for (nPr or nCr)?
Total number of objects.
What does r stand for (nPr or nCr)?
Number to be chosen.
What is the formula for nCr?
n! / r! (n-r)!
What is the mean?
Average
What does σ stand for?
Standard deviation
What does x̅ stand for?
Mean
Besides mean, what are other measures of tendency?
Median and mode
What do variance and standard deviation show?
How much data values deviate from the mean of the data set.
When looking at data variation, if there are small values the data will be
close together.
When looking at data variation, if there are larger values, the data will be
spread out.
What is σx^2?
Variance
What is a function that gives the probability of each outcome in a list of possibilities?
Probability distribution
What has data that vary randomly from the mean?
Normal distribution
What is the graph of a normal distribution called?
Normal curve
In a normal distribution: what percent of data fall within one standard deviation of the mean?
68%
In a normal distribution: what percent of data fall within two standard deviations of the mean?
95%
In a normal distribution: what percent of data fall within three standard deviations of the mean?
99.7%
A normal distribution has a symmetric ____ shape centered on the ____.
bell
mean
Sometimes an extraordinary factor affect data that would otherwise be normal, making it a ______ ____________.
skewed distribution
To find the probability of a value being between two given values on a calculator, hi the _____ menu and chows _________(.
DISTR
normalcdf
