Testing Claims about a Population Proportion Objective: Test a claim about a population proportion

Remember the formulas! If the sample is a simple random sample If np(1-p) > 10 If n < 0.05N

1. State the null and alternative hypotheses. 2. Select a level of significance, α. 3. Compute the test statistic. 4. Determine the critical value. invnorm(α) or invnorm(α/2) 5. Compare the critical value with the test statistic. Reject the H 0 if z 0 falls within the critical region!! 6. State the conclusion.

Pathological gambling is an impulse-control disorder. The American Psychiatric Association lists 10 characteristics that indicate the disorder in its DSM-IV manual. The National Gambling Impact Study Commission randomly selected 2417 adults and found that 35 were pathological gamblers. Is there evidence to support the claim that more than 1% of the adult population are pathological gamblers at the 0.05 level of significance?

(1) State the null and alternative hypotheses H 0 : p=0.01H 1 : p>0.01 (2) Select α α=0.05 (3) Find the z-score (4) z 0 = (4) Find the critical value (4) Determine p-value z 0.5 = p= (5) Compare z-score (5) Compare p-value to critical value to α 2.22>1.645,so reject H < 0.05, so reject H 0 (6) State the conclusion There is sufficient evidence to support the claim that more than 1% of the adult population are pathological gamblers.

STAT TESTS 1-PropZTest Enter the null hypothesis, x, n, and the alternative hypothesis. Calculate

 Obtain a sample of Skittles.  Select one of the five colors. Count the total number of candies as well as the number for the color that you selected.  Is np(1-p) > 10?  Test the claim that the proportion of the color you selected is different from p = 0.2.  Compare your results.  Assignment: page 550 3, 4, 5, 11 – 13, 16, 19, 26