We have to test the null hypothesis that the correlation coefficient p of a bi-variate normal population is 0.2 against the alternative hypothesis that p #0.2. If a random sample of size 11 taken from the population has sample correlation coefficient r = 0.4, what is the value of the standard normal test statistic?
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- Researchers from a certain country were interested in how characteristics of the spleen of residents in their tropical environment compare to those found elsewhere in the world. The researchers randomly sampled 93 males and 107 females in their country. The mean and standard deviation of the spleen lengths for the males were 10.8 cm and 0.9 cm, respectively, and those for the females were 10.2 cm and 0.7 cm, respectively. At the 5% significance level, do the data provide sufficient evidence to conclude that a difference exists in the mean spleen lengths of males and females in the country? Click here to view page 1 of the table of critical values of t. Click here to view page 2 of the table of critical values of t. O E. Ho: H1 H₂ Hai Hg = H2 Compute the test statistic. =(Round to two decimal places as needed.) Determine the critical value(s). t= OF. Ho: H1 H₂ Ha: H1 H₂ 0 (Round to three decimal places as needed. Use a comma to separate answers as needed.) What is the conclusion of the…The average American consumes 86 liters of alcohol per year. Does the average college student consume more alcohol per year? A researcher surveyed 11 randomly selected college students and found that they averaged 95.8 liters of alcohol consumed per year with a standard deviation of 20 liters. What can be concluded at the the a = 0.05 level of significance? a. For this study, we should use t-test for a population mean O b. The null and alternative hypotheses would be: Ho: μ = H₁: μ > O 86 O 86 c. The test statistic (t) = d. The p-value = e. The p-value is ? a f. Based on this, we should Select an answer the null hypothesis. g. Thus, the final conclusion is that ... 1.625 (please show your answer to 3 decimal places.) (Please show your answer to 4 decimal places.) O The data suggest the population mean is not significantly more than 86 at a = 0.05, so there is statistically insignificant evidence to conclude that the population mean amount of alcohol consumed by college students is…A union of restaurant and foodservice workers would like to estimate the mean hourly wage, μ, of foodservice workers in the U.S. this year The mean hourly wage last year was $8.08, and there is good reason to believe that this year's value is different from last year's. The union decides to do a statistical test to see if the value has indeed changed. The union chooses a random sample of this year's wages, computes the mean of the sample to be $7.78, and computes the standard deviation of the sample to be $1.10. Based on this information, complete the parts below. (a) What are the null hypothesis Ho and the alternative hypothesis H₁ that should be used for the test? μ X OSO O>0 H₂ : O H₁ :0 0=0 0#0 (b) Suppose that the union decides to reject the null hypothesis. What sort of error might it be making? (Choose one) ▼ (c) Suppose the true mean hourly wage for foodservice workers in the U.S. this year is $8.08. Fill in the blanks to describe a Type I erro A Type I error would be (Choose…
- A union of restaurant and foodservice workers would like to estimate the mean hourly wage, u, of foodservice workers in the U.S. this year The mean hourly wage last year was $8.08, and there is good reason to believe that this year's value is different from last year's. The union decides to do a statistical test to see if the value has indeed changed. The union chooses a random sample of this year's wages, computes the mean of the sample to be $7.78, and computes the standard deviation of the sample to be $1.20. Based on this information, complete the parts below. (a) What are the null hypothesis H. and the alternative hypothesis H₁ that should be used for the test? H₂ : O H₁ :0 (b) Suppose that the union decides not to reject the null hypothesis. What sort of error might it be making? (Choose one) ▼ (c) Suppose the true mean hourly wage for foodservice workers in the U.S. this year is $8.08. Fill in the blanks to describe a Type I error. A Type I error would be (Choose one) when, in…Scores on a certain "IQ" test for 18-25 year olds are normally distributed. A researcher believes that the average IQ score for students at a certain NJ college is less than 110 points, and so wants to test this hypothesis. The researcher obtain a SRS of 45 student IQ scores from school records and found the mean of the 45 results was 108 with a sample standard deviation of 21. The level of significance (alpha) used for this problem is 0.05. What is the appropriate test statistic (Student must complete by showing by formula using the ap- propriate values in that formula "showing work" and the final answer and appropriate label)? O T test score = (108-110)/(21/sqrt(45)) = -.639 T test score (108-110)/(21/sqrt(45)) = .639 %3D OT test score = (110-108)/(21/sqrt(45)) = .639 %3D T test score (108-110)/(45/sqrt(21)) =-.2037 %3D 素Obtain the confidence limits for the ratio of variances of two normal populations.
- Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2. Step 2 of 3 : Compute the value of the test statistic. Round your answer to two decimal places.The mean number of English courses taken in a two-year time period by male and female college students is believed to be about the same. An experiment is conducted and data are collected from 29 males and 16 females. The males took an average of three English courses with a standard deviation of 0.8. The females took an average of four English courses with a standard deviation of 1.0. Are the means statistically the same? (Assume a 5% level of significance.)A team of researchers found that age distributions in a population of 100,000 people was not Normal. However, after they took a large number of simple random samples, each with (N=100), they observed that the sampling distribution of mean tended toward Normality. Really? Why is it possible?
- A union of restaurant and foodservice workers would like to estimate the mean hourly wage, u, of foodservice workers in the U.S. this year The mean hourly wage last year was $8.16, and there is good reason to believe that this year's value is greater than last year's. The union decides to do a statistical test to see if the value has indeed increased. The union chooses a random sample of this year's wages, computes the mean of the sample to be $8.43, and computes the standard deviation of the sample to be $1.25. Based on this information, complete the parts below. (a) What are the null hypothesis H, and the alternative hypothesis H, that should be used for the test? H, :0 OSO H :0 D=0 (b) Suppose that the union decides not to reject the null hypothesis. What sort of error might it be making? (Choose one) (c) Suppose the true mean hourly wage for foodservice workers in the U.S. this year is $8.16. Fill in the blanks to describe a Type I error. A Type I error would be the hypothesis that…A researcher wants to measure average cardiovascular health of university students and compare those scores to the average scores in the general population. Assuming that population variance is known, what statistical test is most appropriate for this study? independent-samples t-test single-sample t-test z-test for sample mean related-samples t-testA scientist wants to know if the average weight of a particular species of fish is different from 500 grams. He collects a sample of 15 fish and finds that their average weight is 490 grams with a standard deviation of 20 grams. Can he reject the null hypothesis that the true average weight of the fish is 500 grams, using a one sample t-test with a significance level of 0.05?