A commonly cited standard for one-way length (duration) of school bus rides for elementary school children is 30 minutes. A local government office in a rural area randomly samples 100 elementary school children in their district and find an average one-way commute time of 38 minutes with a standard deviation of 8 minutes. Which of the following is the correct set of hypotheses for testing if the average commute time of elementary school students in this district is different than the commonly cited standard of 30 minutes? Họ: H = 30; HẠ: x = 38 %3D O HẠ: H = 30; Ho: x = 30 %3D O Họ: H = 30; HẠ: H = 30 %3D O Ho: x = 38;B На: И = 30

A comparison is made between two bus lines to determine if arrival times of their regular buses from Denver to Durango are off schedule by the same amount of time. For 51 randomly selected runs, bus line A was observed to be off schedule an average time of 53 minutes, with standard deviation 15 minutes. For 60 randomly selected runs, bus line B was observed to be off schedule an average of 60 minutes, with standard deviation 11 minutes. Do the data indicate a significant difference in average off-schedule times? Use a 5% level of significance.   What are we testing in this problem? difference of proportionsdifference of means    single meanpaired differencesingle proportion   (a) What is the level of significance?State the null and alternate hypotheses. H0: ?1 = ?2; H1: ?1 < ?2H0: ?1 = ?2; H1: ?1 ≠ ?2    H0: ?1 > ?2; H1: ?1 = ?2H0: ?1 = ?2; H1: ?1 > ?2 (b) What sampling distribution will you use? What assumptions are you making? The Student's t. We assume that both population…

A USA based cable broadband company wants to investigate whether it's east coasts customers have a higher average customer satisfaction score than compared to it's west coast customers. The customer survey asks for a score between 1 and 5, with 1 being poor and 5 being excellent. 174 east coast customers are surveyed, and the sample mean is 3.35 with a sample standard deviation of 0.51. For the west coast, 355 customers are surveyed, and the sample mean is 3.24 with a sample standard deviation of 0.52.

A computer software vendor claims that a new version of its operating system will crash fewer than six times per year on average. A system administrator installs the operating system and claims that the new operating system will crash more than six times per year on average.   At the end of year, the system administrator samples 41 computers with the new operating system and finds that the mean number of crashes on those computers for the year was 7.1 with sample standard deviation of 3.6 crashes.   Can you conclude that the system administrator’s claim is correct? Use the critical value method to perform a hypothesis test at the 0.05 level of significance.   a. Define the parameter we are testing and setup a hypothesis test to test the administrator’s claim: b. Calculate the test statistics for this hypothesis test. c. What is the critical value for this hypothesis test?