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