We want to investigate an application performances of IOS and ANDROID operating systems. We selected 10 IOS and 10 ANDROID phones randomly and tested whether IOS phones run faster the application or not. We found t statistics by INDEPENDENT SAMPLE T TEST as 1.634. What are the H0 and Ha for this question? IOS phones runs faster the application than ANDROID phones? Why?

Dogsled drivers, known as mushers, use several different breeds of dogs to pull their sleds. One proponent of Siberian Huskies believes that sleds pulled by Siberian Huskies are faster than sleds pulled by other breeds. He times 4040 teams of Siberian Huskies on a particular short course, and they have a mean time of 7.77.7 minutes. The mean time on the same course for 4747 teams of other breeds of sled dogs is 6.26.2 minutes. Assume that the times on this course have a population standard deviation of 1.51.5 minutes for teams of Siberian Huskies and 1.61.6 minutes for teams of other breeds of sled dogs. Let Population 1 be sleds pulled by Siberian Huskies and let Population 2 be sleds pulled by other breeds.   Step 1 of 2 :   Construct a 95%95% confidence interval for the true difference between the mean times on this course for teams of Siberian Huskies and teams of other breeds of sled dogs. Round the endpoints of the interval to one decimal place, if necessary.

Each year, marketing and information firm J.D. Power and Associates surveys new car owners 90 days after they have purchased their cars. The data collected are used to rate auto brands (Toyota, Ford, and others) on initial quality and initial customer satisfaction. USA Today reported both the number of manufacturing defects per 100 vehicles and a satisfaction score for all 33 brands sold in the United States.+ A research group decides to compare the mean number of defects for 2 specific models of cars, A and B, made this year by taking random samples of 100 cars of each model. USE SALT (a) After collecting the data, the research group calculates a 95% confidence interval to estimate the difference in population means. In this case, what is the population? O the defects O all cars made this year all cars for models A and B that were produced this year O the 100 cars from each model (b) Suppose the calculated confidence interval is (100, 104) number of defects. What is the value of the…

Describe a study in which you can use both nonparametric and parametric statistics. A researcher has participants expecting to receive either painful or mild electrical shocks during a study wait in a quarter-full waiting room with other participants. He then measures whether they choose to sit next to other participants or if they sit far away on their own. What is the best test to run for this study and why?

A researcher wanted to find the best viewing distance for watching a TV screen. He recruited the following number of participants and asked them to evaluate their satisfaction of the viewing distance. Then, he conducted an ANOVA to see if there is any significant mean differences. Here are the number of participants by each group: Group 1 (4 feet) - 5 people Group 2 (7 feet) - 5 people Group 3 (10 feet) - 6 people Group 4 (13 feet) - 5 people Group 5 (16 feet) - 4 people Given the numbers as presented above, what is the degrees of freedom for within groups for this analysis? a. 4 b. 20 O c. 21 d. 25

There are many ways to measure the reading ability of children. One frequently used test is the DRP or Degree of Reading Power. The national average score in DRP test is 32. We want to determine if there is sufficient evidence at the 5% level to suggest that the mean score of all third graders in YOUR district is higher than the national mean. The DRP scores for a simple random sample of 41 third graders in that suburban school in YOUR district yielded a mean of 35.2. Assume that the population of DRP scores of third graders in that suburban school district are normally distributed with a population std.dev of 11.

A nationwide job recruiting firm wants to compare the annual incomes for childcare workers in Connecticut and California. Due to recent trends in the childcare industry, the firm suspects that the that the mean annual income of childcare workers in the state of Connecticut is greater than the mean annual income of childcare workers in California. To see if this is true, the firm selected a random sample of 10 childcare workers from Connecticut and an independent random sample of 10 childcare workers from California and asked them to report their mean annual income. The data obtained were as follows. 80°F Partly sunny Annual income in dollars Connecticut 42438, 52287, 46837, 49334, 52848, 52929, 57111, 51860, 44967, 52174 California 50998, 38334, 56804, 50919, 49446, 41141, 45717, 43963, 55156, 47295 LL D 144Hz Send data to calculator V The population standard deviations for the annual incomes of childcare workers in Connecticut and in California are estimated as 6300 and 6100,…

A community college professor is interested in determining the relationship between the number of posts students make on Schoology and their respective grades. He planned to correlate the results from a sample from all his classes, however, due to time constraints, he decided to sample only from students with high grades. As his statistical consultant, state whether or not you support his plans and why.