Question

8. Hypothesis testing, problem 4 Aa Aa Microsoft Outlook is believed to be the most widely used e-mail manager. A Microsoft executive claims that Outlook is used by at least 75% of Internet users. A Merrill Lynch study involving 200 respondents reported that 68% use Microsoft Outlook. Can you prove that the executive's claim is not valid? What is the relevant point estimate? What is the value of the test statistic? This test statistic has: O A t distribution with 198 degrees of freedom O A normal distribution O A t distribution with 200 degrees of freedom O A t distribution with 199 degrees of freedom A standard normal distribution What is the p-value for this test? Allowing a 5% chance of a Type 1 error, what is your conclusion for this test? O Reject the null hypothesis, and conclude that the Microsoft executive's claim is not valid. O Reject the null hypothesis, and conclude that there is insufficient evidence that the Microsoft executive's claim is not valid. O Do not reject the null hypothesis, and conclude that there is insufficient evidence that the Microsoft executive's claim is valid. O Do not reject the null hypothesis, and conclude that the Microsoft executive's claim is not valid. O Do not reject the null hypothesis, and conclude that the Microsoft executive's claim is valid

Answer 1

This is an one proportion z test. This is done to test a sample result against an existing claim. a null hypothesis and an alternative hypothesis are formed and tested.

a-0.05 The executive is claiming that outlook is used by at least 75% of internet users. Therefore only way to disprove the claim would be to test whether the true proposition is less than 75% Ho: p 0.75 Hai p<0.75 z (0.68-0.75)/[(0.75*025) (200)]--2.286190-2.3 What is the relevant point estimate? 0.68 What is the value of the test statistics? -2.3 This statistics has A normal distribution A t distribution with 199 degrees of freedom A t distribution with 200 degrees of freedom P value for this test Right tailed p value: P (Z> z)-0.9860966 P value is greater than a 0.05. hypothesis, and therefore cannot prove that the executive's claim is invalid. Allowing a 5% chance of a Type 1 error, what is your conclusion for this test? Since the p value is greater than a- 0.05, we fail to reject the null Do not reject the null lypothesis, and conclude that the Microsoft executive's claim is valid.