davenport stat500 week 5 quiz ch 8 and 9 davenport stat500 week 5 quiz ch 8 and 9 Question · Express the null hypothesis and alternative hypothesis in symbolic form. The manufacturer of a refrigerator system for beer kegs produces refrigerators that are supposed to maintain a true mean temperature,?, of 48°F, ideal for a certain type of German pilsner. The owner of the brewery does not agree with the refrigerator manufacturer, and claims he can prove that the true mean temperature is incorrect. Save your time! Proper editing and formatting Free revision, title page, and bibliography Flexible prices and money-back guarantee ORDER NOW · Question 2 5 out of 5 points Assume that the data have a normal distribution and the number of observations is greater than 50. Find the critical z value used to test null hypothesis. ? = 0.05 for a two-tailed test Make sure you submit a unique essay Our writers will provide you with an essay sample written from scratch: any topic, any deadline, any instructions. 100% ORIGINAL ORDER NOW · Question 3 5 out of 5 points Formulate the indicated conclusion in nontechincal terms. Be sure to address the original claim. A researcher claims that the amounts of acetaminophen in a certain brand of cold tablets have a standard deviation different from the ? = 2.5mg claimed by the manufacturer. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is failure to reject the null hypothesis, what should the researcher conclude? · Question 4 5 out of 5 points Assume that a hypothesis test of the given claim will be conducted. Identify the type I or type II error for the test. A medical researcher claims that 20% of children suffer from a certain disorder. Identify the type I error for the test. · Question 5 9 out of 10 points Identify the null hypothesis and alternative hypothesis in symbols, test statistic, p-value, conclusion about the null hypothesis, and final conclusion that addresses the original claim. Various temperature measurements are recorded at different times for a particular city. The mean of 20 degrees C is obtained for 40 temperatures on 40 different days. Assuming that ? = 1.5 degrees C, test the claim that the population mean is 22 degrees C. Use a .05 level of significance. · Question 6 5 out of 5 points In the context of a hypothesis test for two proportions, which of the following statements about the pooled sample proportion, p, is/are true? I. It estimates the common value of p1 and p2 under the assumption of equal proportions. II. It is obtained by averaging the two sample proportions p1 and p2. III. It is equal to the proportion of successes in both samples combined. · Question 7 5 out of 5 points Assume that you plan to use a significance level of ? =0.05 to test the claim that p1 = p2. use the given sample sizes and numbers of successes to find the z test statistic for the hypothesis test. In a vote on the Clean Water bill, 44% of the 205 Democrats voted for the bill while 46% of the 230 Republicans voted for it. · Question 8 5 out of 5 points Determine whether the samples are independent or dependent. Select the appropriate definition. The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group of patients who use a placebo drug. · Question 9 5 out of 5 points State what the given confidence interval suggests about the two population means. A researcher was interested in comparing the time spent watching television by women and by men. Independent simple random samples of 14 women and 17 men were selected, and each person was asked how many hours he or she had watched television during the previous week. The summary statistics are as follows: Women Men Mean x1 = 12.9 hrs Mean x2 = 14 hrs s1 = 3.9 hrs s2 = 5.2 hrs The following 99% confidence interval was obtained for ?1-?2, the difference between the mean amount of time spent watching television for women and the mean amount of time spent watching television for men: -5.61 hrs <?1-?2<3.41 hrs. What does the confidence interval suggest about the population means? · Question 10 5 out of 10 points Use the computer display to solve the problem. When testing for a difference between the means of a treatment and a placebo group, the computer display below is obtained. using a 0.05 significance level, is there sufficient evidence to support the claim that the treatment group (variable 1) comes from a population with a mean that is less than the mean for the placebo population (variable 2). Explain. State your conclusion. t test: Two Samples for Means Variable 1 (Treatment) Variable 2 (Placebo) Mean 65.10738 66.18251 Known variance 8.102938 10.27387 Observations 50 50 Hypothesized mean difference 0 t -1.773417 P(T<t) one-tail 0.0384 t critical one-tail 1.644853 P(T<t) two-tail 0.0768 t critical two-tail 1.959961