Exam 2 Review - Chapter 6 Flashcards
What are the properties of the normal curve?
- unimodal
- bell curve
- symmetrical
What is standard normal distribution?
A normal distribution with a mean of 0 and a standard deviation of 1. N(0,1)
What is a z score?
A standardized score (sample mean - population mean)/standard deviation
How do you convert a raw score to a z score?
Subtract the mean from each data point, then divide each resulting difference by the standard deviation.
How do you convert a z score to a raw score?
Multiply the z score by the standard deviation and add the mean.
What does a z score of 0 represent?
The data point in question is the same as the mean.
Why do we standardize scores?
It translates questions to put them on the same scale/makes different things comparable.
What is the Central Limit Theorem?
Refers to how a distribution of sample means is a more normal distribution than a distribution of scores.
What is a distribution of means?
A distribution composed of means that are calculated from all possible samples of a given size, taken from the same population.
What three properties do distributions of means have?
- The distribution of means has the same mean as the population distribution of scores
- The distribution of means has less variability than the distribution of scores
- The distribution of means becomes more normally distributed
What is standard error?
The standard deviation of means.
How do you calculate standard error?
Divide the standard deviation by the square root of the sample size (N)
How do you find a z statistic for a single mean in a distribution of means?
Subtract the distribution of means from the sample mean, then divide by the standard error.
