Chapter 6 Flashcards
Probability Distribution
Gives all possible events a certain variable can produce and the probabilities for each of these events/values. Ex brown eyes 79 percent
Random variable
a numerical measurement of the outcome of a random phenomenon.
What are the two properties of probability distribution?
1) All probabilities must be between 0 and 1.
2) All the probabilities must sum up to 1.
Expected value
The long-run average result of a random variable.
u
Mu. E[X]= Sigma x* P[x}. We take each outcome, multiply by its probability, and sum those products.
T/F With continuous random variables, we will be looking at intervals instead of values
True.
Standard normal distribution
A normal distribution with a mean of 0 and a standard deviation of 1.
T/F Z-scores not follow the standard distribution.
False, they will follow the standard distribution.
T/F For any indiviudal value in a carinuous distribution, the theoretical probability of observing a particular number as the result of the trail is 0
True.
A binomial distribution has the following properties:
1) Each of n trails has two possible outcomes. The outcome of interest is called a success and the other outcome is called a failure.
2) Each trial has the same probability of success. This is denoted by p, so that the probability of a success is p and the probability of failure is q=1-p.
3) The n trials are independent. That is, the result for one trial does not depend on the results of other trials.
4. We have a fixed number of trails.
n
number of trials for a binomial distribution
p
probaility of success (binomial distribution)
q
probability of failure. q=1-p (binomial distribution)
X
the number of successes for n trials
n and p are the ____ of the binomial _____ ________
parameters, random variable.
