Hypothesis testing Lesson outcomes • Define the hypothesis testing • Identify the general steps of hypothesis testing • Describe • null & alternative hypothesis • level of significance • test statistic • critical & p-values • rejection region • Differentiate between two-tailed test & one-tailed test • Clarify Type I & Type II errors
Basic concepts Hypotheses: • Null hypothesis • Alternative hypothesis
Rejection region: • Significance level
Decision rule: • Critical value • P-value
Definition Hypothesis • A statement about the parameters of one or more populations • Population mean • Population proportion
Definition Hypothesis • A statement about the parameters of one or more populations • Population mean • Population proportion
1.Definition Hypothesis testing • A method/ standard procedure for testing a statement • A process that uses sample statistics to test a claim • An inferential method • To analyze evidence that data provide • To make decisions based on data
2. Types of error Possibility of making the wrong decision • decision is based on a sample
Types of error Type I error • the mistake of rejecting the null hypothesis when it is actually true. • The symbol α (alpha) is used to represent the probability of a type I error.
Type II error • the mistake of failing to reject the null hypothesis when it is actually false. • The symbol (beta) is used to represent the probability of a type II error
3. Steps for hypothesis testing ≠
STEP 1: • State the hypotheses
STEP 2: • Select the significance level
STEP 3: • Identify the test statistic to use
STEP 4: • Formulate the decision rule
STEP 5: • Make the statistical desicion