Question

Make sure to show all steps to receive full credit, that is: a) Identify the claim: state the null and alternative hypotheses. b) Determine the test: left-tailed, right-tailed, or two-tailed. c) Graph your bell-shaped curve and label your levels of significance or critical value. d) Find your standardized test statistic ? and label it on your graph. e) Decide whether to reject or fail to reject the null hypothesis. f) Interpret your result.

1) A medical researcher suspects that the pulse rate of smokers is higher than the pulse rate of non-smokers. Test the researcher's suspicion using ? = 0.05. Assume the two samples are random and independent.

Smokers    Nonsmokers

?1 = 100 ?2 = 100

?̅1 = 85 ?̅2 = 80

?1 = 4.6 ?1 = 5.5

Answer 1

Solution :

a) Claim is as follows :

The null and alternative hypotheses would be as follows :

b) The test is right-tailed test.

c) Significance level = 0.05

The right-tailed critical z-value at 0.05 significance level is given as follows :

Critical value = Z_(0.05) = 1.645

The curve is given below :

d) The standardized test statistic is given as follows :

We have following values :

The standardized test statistic is, Z = 6.9734.

e) Test statistic = 6.9734

Critical value (right-tailed) = 1.645

(6.9734 > 1.645)

Since, value of the standardized test statistic is greater than right-tailed critical value of z, therefore we shall reject the null hypothesis.

f) At 0.05 significance level, there is sufficient evidence to conclude that pulse rate of smokers is higher than the pulse rate of non-smokers.