statistical hypothesis

a conjecture about a population parameter

null hypothesis

a statistical hypothesis that states that there is no difference between a parameter and a specific value

alternative hypothesis

a statistical hypothesis that states the existence of a difference between a parameter and a specific value

hypothesis testing

a decision making process for the population under study

statistical test

uses the data obtained from a sample to make a decision about whether a null hypothesis should be rejected

test value

the numerical value obtained from a statistical test

type I error

occurs when you reject the null hypothesis when it is true

type II error

occurs when you do not reject the null hypothesis when it is false

level of significance

the maximum probability of committing a type I error

probability of a type I error symbol

probability of a type II error symbol

critical value

separates the critical region from the noncritical region

critical region

the range of values of the test value that indicates there is a significant different and the null hypothesis should be rejected

noncritical region

the range of values of the test value that indicates that the difference was probably due to chance and that the null hypothesis should not be rejected

one-tailed test

the null hypothesis should be rejected when the test value is in the critical region on one side of the mean

two-tailed test

the null hypothesis should be rejected when the test value is in either of the 2 critical regions

z-test

a statistical test for the mean of a population

p-value

the probability of getting a sample statistic or a more extreme sample statistic in the direction of the alternative hypothesis when the null hypothesis is true

t test

a statistical test for the mean of a population & is used when the population is normally or approximately normally distributed