ch 8

hypothesis testing

decision making process for evaluating claims about pop

• traditional method

• p-value method

• confidence interval method

statistical hypothesis

conjecture abt pop parameter → may or may not be true

null hypothesis

type of stat hypo:

• states there is no dif between parameter and specific value

alternative hypothesis

type of stat hypo:

• states there is a dif between parameter and specific value

• sometimes called research hypo.

claim

a _____ can be stated as either null or alt. hypo

• stat evi. only support if it is the alt. hypo

  • can be used to reject if it is null hypo

type i error

occurs if null hypo is true and rejected

type ii error

occurs if null hypo is false and not rejected

level of significance

maximum prob of committing a type I error

critical rejection

_____ or _____ region

• range of test values indicates significant difference

  • null hypo should be rejected

noncritical nonrejection

_____ or _____ region

• range of test values indicates dif was prob due to chance

  • null hypo should NOT be rejected

critical value

seperates critical region from noncritical region

• C. V.

probability value

probability of getting a sample stat. in direction of alt hypo when null hypo is true

• actual area under standard ND curve

p value

____-____ <= a, reject null hypo

p value

____-____ > a, do not reject null hypo

alpha

area in tail of distr outside of C. V.

• prob. of committing a type I error

t test

test for pop mean when

• pop is ND

• pop SD isn’t known

standard normal distr

t distr differes from ____ ____ ____:

• variance > 1

• t is fam of curves based on d. f.

• as sample size increases, t approaches ND

four

p-values are usually expressed in ____ decimal places

z

a __-test is used for hypo testing involving proportions

proportion

assumptions for testing a _____:

• sample is random

• binom exp conditions satisfied

• np >= 5 & nq>=5

chi squared

a ____-____ hypo test can be used for a single variance

chi squared

___-____ test assumptions:

• random sample

• normal distr.

• observations independent of each other