A chain of restaurants advertises that the mean wait time, , for a customer is at most 9 minutes. To test the restaurant chain's claim, a consumer advocate takes a random sample of 44 customers. The mean wait time for the sample is 10.4 minutes. Assume the population standard deviation for the wait times is known to be 4.1 minutes. Is there enough evidence to reject the claim that the mean wait time is at most 9 minutes? Perform a hypothesis test, using the o.0s level of significance. (a) State the null hypothesis H, and the alternative hypothesis H,.

The mean age of bus drivers in chicago is 56.7 years. If a hypothesis test is performed, how should you interpret a decision that rejects the null hypothesis?

An online stock trading company makes part of their revenue from clients when the clients trade stocks therefore, it is important to the company to have an good idea of how many trades its clients are making in a given year. In a sample of 98 clients of an online stock trading company, the average number of trades per year was 85 with a standard deviation of 17. If you were to test the hypothesis that the average number of trades per year is greater than the previous year when the average number of trades was 84 (using the 10% level of significance), what is the critical value? (please round your answer to 2 decimal places)

A study by the department of education of a certain state was trying to determine the mean SAT scores of the graduating high school seniors. The study examined the scores of a random sample of 190 graduating seniors and found the mean score to be 520 with a standard deviation of 87. Determine a 95% confidence interval for the mean, rounding all values to the nearest tenth.

An online stock trading company makes part of their revenue from clients when the clients trade stocks therefore, it is important to the company to have an good idea of how many trades its clients are making in a given year. In a sample of 120 clients of an online stock trading company, the average number of trades per year was 82 with a standard deviation of 16. If you were to test the hypothesis that the average number of trades per year is different than the previous year when the average number of trades was 85 (using the 10% level of significance), the test statistic is -2.05 and the critical value is ± 1.65 . What is your conclusion concerning the null hypothesis?     Reject the null hypothesis     Fail to reject the null hypothesis

If the sample mean is 8, the hypothesized population mean is 4, and the population standard deviation is 2, compute the test value needed for the z test.