Two soap brands have a competition over the longevity of their bars. A sample of 21 bars from company A lasts an average of 13.1 days with a sample variance of 21.2. A sample of 24 bars from company B lasts for an average 10.3 days with a sample variance of 19.3. Test to see if company A’s variance is larger than company B's variance using a 5% level of significance. The null hypothesis is that the variances are the same. The alternate hypothesis is that company A’s variance is larger than company B’s variance. Report your conclusion: a) fail to reject the null hypothesis b) reject the null hypothesis

Research has shown that, for baseball players, good hip range of motion results in improved performance and decreased body stress. A research article reported on a study of independent samples of 40 professional pitchers and 40 professional position players. For the pitchers, the sample mean hip range of motion was 75.5 degrees and the sample standard deviation was 5.8 degrees, whereas the sample mean and sample standard deviation for position players were 79.1 degrees and 7.1 degrees, respectively. Assuming that the two samples are representative of professional baseball pitchers and position players, test hypotheses appropriate for determining if there is convincing evidence that the mean range of motion for pitchers is less than the mean for position players. (Use  ? = 0.05.  Use ?1 for pitchers and ?2 for position players.) State the appropriate null and alternative hypotheses.   Find the test statistic and P-value. (Use SALT. Round your test statistic to one decimal place and…

An electronic company's records show that the mean number of circuit.boards rejected per batch is 5.7 with a variance of 1.4. Due to a change in the molding process, factory management has hired you to perform a hypothesis test to check if the variance, o, has increased. To do so, you test a random sample of 10 batches produced using the new process; the number of circuit boards rejected per batch has a sample variance of 2.5. Under the assumption that the number of circuit boards rejected per batch using the new process follows a normal distribution, you will perform a chi-square test. Find x, the value of the test statistic for your chi-square test. Round your answer to three or more decimal places. * = 0

An engineer designed a valve that will regulate water pressure on an automobile engine. The engineer designed the valve such that it would produce a mean pressure of 7.4 pounds/square inch. It is believed that the valve performs above the specifications. The valve was tested on 280 engines and the mean pressure was 7.5 pounds/square inch. Assume the variance is known to be 0.81. A level of significance of 0.05 will be used. Make a decision to reject or fail to reject the null hypothesis. Make a decision. Answer O Reject Null Hypothesis O Fail to Reject Null Hypothesis Tables: Keypad Keyboard Shortcut