D: H > L E: h < l F: H < L
Which of these hypotheses is the most appropriate alternativehypothesis for this problem? (Q2) ? A: h = l B: H = L C: H <
Suppose that the population distributions of the number of emails sent in the by high-speed-connection customers and bylow-speed-connection customers both are nearly normal. Which of the following have probability histograms that can be approximated well by a normal curve, after transforming to standard units? (select all that apply)(Q3) ? A: h B: H - L C: h - l D: H E: l F: LSuppose we construct a Z statistic by transforming H - L to standard units (approximately). Under the alternative hypothesis, the expected value of Zwould be (Q4) ? A:
To test the null hypothesis at significance level 10%, we should reject the null hypothesis if (Q6) ? A: the z-score B:
For high-speed-connection customers, the sample mean number of emails in the month is 424, and the sample standard deviation of the number of emails in the the month is 124. For low-speed-connection customers, the sample meannumber of emails in the month is 408, and the sample standard deviation of the number of emails in the month is 138.