If you have samples of n₁ = 22 and n₂ = 19, in performing the pooled-variance t test, how many degrees of freedom do you have? You have degrees of freedom.
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Q: An environmentalist wishes to conduct a hypothesis test on the percentage of cars driven in the city…
A: Sample size(n)=143 Population proportion(P)=0.04 q=1-p q=1-0.04=0.96
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A: We know that
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A: From the provided information, Sample size (n1) = 30 and n2 = 30 Level of significance (α) = 0.05
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A: Given iMessage ; n1=40 , average=280 , Sample variance=170 What's App; n2=40 , average=295 , Sample…
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Q: If you have samples of n₁ = 22 and n₂ = 19, in performing the pooled-variance t test, how many…
A: It is given that Sample size of first sample n1 = 22 Sample size of second sample n2 = 19
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A: Given: For Longboard n1=30, X¯1=12.40 S1=5.4431 For Shortboard n2=30, X¯2=10.03 S2=4.9514
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- Acne is a common skin disease that affects most adolescents and can continue into adulthood. A study compared the effectiveness of three acne treatments and a placebo, all in gel form, applied twice daily for 12 weeks. The study's 517 teenage volunteers were randomly assigned to one of the four treatments. Success was assessed as clear or almost clear skin at the end of the 12 week period. The results of the study can be seen in the table below. Using the appropriate statistical test, determine if there is significant evidence that the four treatments perform differently. If so, how do they compare.Fewer young people are driving. In 1995, 63.9% of people under 20 years old who were eligible had a driver's license. Bloomberg reported that percentage had dropped to 41.7% in 2016. Suppose these results are based on a random sample of 1,200 people under 20 years old who were eligible to have a driver's license in 1995 and again in 2016.Use the following information to answer the question. A researcher wants to study different messaging platforms by collecting data on 40 individuals. Half of the individuals only use iMessage while the other half only use What's App. For the individuals who only used iMessage, they sent an average of 280 messages with a sample variance of 170 in the past week. For the individuals who only used What's App, they sent an average of 295 messages with a sample variance of 182 in the past week. Determine if there is a significant difference between the average messages sent between the two groups of individuals. Use a significance level of 1%. What is the null hypothesis? Group of answer choices A. The iMessage group on average sent more messages than the What's App group. B. The iMessage group on average sent less messages than the What's App group. C. There is no difference in the average number of messages sent between the two groups. D. There is a difference in the average…
- A hospital claims that 40% of its patients request a telephone. you are interested in disproving this claim. you select a random sample of 250 patients and find that 85% requested a telephone. what is the test statistic for this test?It has been found that 25.1% of men (Group 1) 20 years and older suffer from hypertension (high blood pressure) and 33.9% of women (Group 2) are hypertensive. A random sample of 164 of each gender was selected from recent hospital records, and the following results were obtained. Can you conclude that a higher percentage of women have high blood pressure? Use =0.05. Men: 42 patients had high blood pressure Women: 52 patients had high blood pressure Required: Test Value Only the final answer should be rounded-off to TWO decimal places.If you have samples of n1=19 and n2=24, in performing the pooled-variance t test, how many degrees of freedom do you have?
- If you have samples of n1=19 and n2=17, in performing the pooled-variance t test, how many degrees of freedom do you have? You have __ degrees of freedom.In college, talented runners may join a cross-country team. Runners tend to run their best times when they run even splits. Even splits occur when the runners maintain an even pace throughout the race. The cross-country coach wants to estimate the typical variability in his best runner's 1-mile splits. He takes a random sample of 25 of this runner's mile splits and finds that this runner's mean 1-mile split is 5.44 minutes per mile, with a standard deviation of 0.14 minutes per mile. This runner's 1-mile splits follow a normal distribution. (a) Find the chi-square critical values XL² and Xu² to be used in constructing a 95% confidence interval for the true population standard deviation. (Round your answers to two decimal places.) XL²= XU²= (b) Find the 95% confidence interval for the true variability in his best runner's 1-mile splits. (Round your answers to three decimal places.) lower bound and the upper bound(OPHTHALMOLOGY) The following data are from a study on Botox injections. Patients received a high-dose injection in one eye (experimental treatment = treatment E) and a low-dose injection in the other eye (control treatment = treatment C). Patients were asked to rate the level of pain in each eye on a 1–10 scale, with higher scores indicating more pain. The assignment of treatments to eyes was randomized. The subjects came back over several visits. Data from the last visit are given in the following table: 1. Which of the following is the correct test to conduct given the situation above? 2. The hypotheses are: 3. What is the level of significance? 4. What is the computed test statistic? Hint: Use (mean of "Pain in E eye") minus (mean of "Pain in C eye") 5. What is the correct decision based on the p-value or critical value method?
- A dowser has correctly located water for a well 1 out of 2 times in Jones County. In Jones County, someone who is just guessing has a 40% chance of locating water for a well. Does this sample provide sufficient evidence that the dowser can locate water and is not just guessing?Any basketball fan knows that Shaquille O'Neal, one of the NBA's most dominant centers of the last twenty years, always had difficulty shooting free throws. Over the course of his career, his overall made free-throw percentage was 53.3%. During one off- season, Shag had been working with an assistant coach on his free-throw technique. During the next season, a simple random sample showed that Shaq made 26 of 39 free-throw attempts. Test the claim that Shaq has significantly improved his free-throw shooting using a 0.05 significance level. Check the conditions of the Central Limit Theorem for this scenario. Calculate the number of expected successes.Primary seat belt laws allow police to stop a motorist for not wearing a seat belt. According to the National Highway Traffic Safety Administration, the percentage of drivers wearing seat belts in the Limpopo province was 68.5% in 2017 and 72% in 2018. Assume that these percentages are based on random samples of 1000 drivers in 2017 and 1050 in 2018. Suppose you must test at 5% level of significance whether the proportion of all drivers in Limpopo province who used seat belts in 2017 is lower than that for 2018. 1 Questions I) Determine the alternative hypothesis to be tested: II) Determine the value of test statistic: III) Determine the p-value for this problem: IV) the conclusion Since Z=-1.734 is greater than Z subscript 0.05 end subscript equals negative 1.645, we then reject the null hypothesis at 5% level of significance and conclude that the proportion of all drivers in Limpopo province who used seat belts in 2017 is lower than that for 2018. b) Since Z=-1.734 is less…