There are two statistical tests for mean: 1) z test – Used for large samples (n ≥ 30) 1) t test – Used for small samples (n < 30)

Test Value = (Observed Value) – (Expected Value) Standard Error * The observed value is the statistic that is computed from the sample data. ** The expected value is the “hypothesized value.”

t.v.= ( X – µ ) X = ( σ / √n ) Sample mean µ =Hypothesized Value σ =Standard Deviation n =Sample Size

1)State the null and alternative hypotheses 2)Find the critical value(s) 3)Compute the test value 4)Make the decision to either “reject the null” or “not reject the null”