L6 - Normal Curved and Z scores Flashcards
what is Probability Distribution?
it is a List of all the possible outcomes of a random variable along with their corresponding probability values
what is Normal distribution?
distribution of values based on the normal curve
What is Central limit Theorem?
It allows the study of a sample to be valid for making inferences about a normally distributed Infinite population.
AS sample size increases the distribution of sample means of size n, randomly selected, approaches a normal distribution.
Why do we use Normal curves?
if a variable is approximately normally distributed we can make inferences about values of that variable.
What two parameters control the shape of the Normal Curve?
Standard deviation and the Mean.
The standard Normal Distribution ( Z scores)
all Normal Distributions can be converted into the standard normal curve by subtracting the mean and dividing by the standard deviation.
what is the area under the normal curve Equal to?
Probability
what is the total area under a normal curve?
1.0
what is a useful property of a normal curve?
they are symmetrical.
