Does a stress reduction program help reduce stress in high school students at Alphabet High?  The population of interest is all students at Alphabet High.  The mean stress level for all students at the high school is 50 with a standard deviation of 7.  A sample of 20 students participated in a stress reduction program, after which the sample’s mean stress level was 45.  Conduct hypothesis testing (one-tailed) with alpha = .03 What is the appropriate critical z value for this problem?  Calculate the observed z (test statistic)  What is the effect size for the stress reduction program? (give the specific value)

Suppose that a Normal model describes furl economy (mile per gallon) for automobile and that a Saturn has a standardized score ( z score) of +2.2. This meatn taht Satturn.... gets 2.2 miler sper gallon. get 2.2 times the gas mileage of the avereage car. get 2.2 mpg more than the average car. have a standard deviation of 2.2 mpg achieve fuel eceonomy that is 2.2 standard deviations better thean the average car.

Currently patrons at the library speak at an average of 66 decibels. Will this average decline after the installation of a new computer plug in station? After the plug in station was built, the librarian randomly recorded 66 people speaking at the library. Their average decibel level was 63.2 and their standard deviation was 18. What can be concluded at the the a = 0.10 level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho: ?v Select an answer v Hị: Select an answer c. The test statistic ? v (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is ? va f. Based on this, we should Select an answer g. Thus, the final conclusion is that ... | the null hypothesis. OThe data suggest that the population mean decibal level has not significantly decreased from 66 at a = 0.10, so there is statistically insignificant evidence to conclude that the…

#4data: 0.06, 0.11, 0.16, 0.15, 0.14, 0.08, 0.15. Use the sample data from #4 to construct a 98% confidence interval estimate for the standard deviation of the amount nitrogen-oxide emission for all cars.

Records indicate that the mean weight of mature rainbow trout in Eagle Creek is 1.75 kg with a standard deviation of 0.33 kg. After years of marked oxygen depletion from pollutants in the creek, a biologist wants to see if the standard deviation, o, of weights has changed. The biologist measures the weights of 20 randomly chosen mature rainbow trout from the creek and finds that the sample standard deviation is 0.38 kg. Assume the current weights of mature rainbow trout in the creek follow a normal distribution. Does the biologist have sufficient evidence to conclude that the population standard deviation, o, differs from 0.33 kg? To answer, complete the parts below to perform a hypothesis test. Use the 0.10 level of significance.

The average American consumes 89 liters of alcohol per year. Does the average college student consume less alcohol per year? A researcher surveyed 15 randomly selected college students and found that they averaged 87.3 liters of alcohol consumed per year with a standard deviation of 15 liters. What can be concluded at the the a = 0.05 level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Но: ? Select an answer V Н: ? v Select an answer V c. The test statistic ? v = (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is ? v a f. Based on this, we should Select an answer g. Thus, the final conclusion is that ... the null hypothesis. O The data suggest the population mean is not significantly less than 89 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 weight loss program based on exercise more effective than a program based on diet? The 44 overwelght people put on a strict one year exercise program lost an average of 30 pounds with a standard devilation of 10 pounds. The 50 overweight people put on a strict one year diet lost an average of 25 pounds with a standard deviation of 9 pounds. What can be concluded at the a = 0.01 level of signtficance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho: Select an answerv Select an answerv Select an answerv (please enter a decimal) H: Select an answerv Select an answerv Select an answerv (Please enter a decimal) C. The test statistic ?v = (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is ?v a f. Based on this, we should Select an answerv the null hypothesis. g. Thus, the final conclusion is that... O The results are statistically insignificant at a = 0.01,…

Is it more expensive to live in California or Florida? Monthly cost of living expenses for California are approximately Normal with mean μC=$10,800��=$10,800 and standard deviation σC=$3,200��=$3,200. Monthly cost of living expenses for Florida are approximately Normal with mean μF=$8,500��=$8,500 and standard deviation σF=$2,700.��=$2,700. Suppose we select independent SRSs of 16 residents of California and 9 residents of Florida and calculate the sample mean monthly cost of living, x¯C�¯� and x¯F�¯�. a. What is the shape of the sampling distribution of x¯C−x¯F?�¯�−�¯�? Why? b. Find the mean and standard deviation of the sampling distribution of x¯C−x¯F�¯�−�¯�. c. Calculate the probability that the average monthly cost of living expense of the 16 randomly selected California residents is less than the average monthly cost of living expense of the 9 randomly selected Florida residents.

You want to buy a washing​ machine, and a salesperson tells you that the mean repair costs for Model A and Model B are equal. You research the repair costs. The mean repair cost of 24 Model A washing machines is ​$209. Assume the population standard deviation is ​$20. The mean repair cost of 27 Model B washing machines is ​$215. Assume the population standard deviation is ​$24. At α=0.01, can you reject the​ salesperson's claim? Assume the samples are random and​ independent, and the populations are normally distributed. Complete parts​ (a) through​ (e). ​(a) Identify the claim and state H0 and Ha.   What is the​ claim?     A. The mean repair costs for Model A and Model B are equal.   B. The mean repair cost for Model A is greater than Model B.   C. The mean repair costs for Model A and Model B are different.   D. The mean repair cost for Model A is less than Model B. Let μ1 be the mean repair cost for Model A and let μ2 be the mean repair cost for Model B.…