The mean serum cholesterol in American males over 60 years of age is 220 with a standard deviation of 21. An investigator wants to test if the mean serum cholesterol is different in males over 60 years of age living in Mediterranean regions.  The investigator plans to perform a two-sided hypothesis test and want to be 95% confident that she can detect a difference of 20 points in mean total cholesterol level with 80% statistical power. She assumes that 10% of the participants will be lost to follow-up during the study. How many males over 60 years of age living in Mediterranean regions must be enrolled in the study?

Given that the researcher wants to be sure the mean difference in the change in hemoglobin levels has a margin of error no more than 0.2 g/dL and the difference in the stand deviation between the mean hemoglobin levels for the two forms of iron supplements used to treat anemia is 1.2 g/dL, what is the desired number of recruits for the study, assuming the individuals will participate in a crossover trial, if the study’s attrition rate is expected to be .25? Group of answer choices n = 139 n = 554 n = 185 n = 55,320

The mean age when smokers first start is 13 years old with a population standard deviation of 1.8 years. A researcher thinks that smoking age has significantly changed since the invention of ENDS—electronic nicotine delivery systems. A survey of smokers of this generation was done to see if the mean age has changed. The sample of 31 smokers found that their mean starting age was 12.4 years old. Do the data support the claim at the 10% significance level? What are the correct hypotheses? H0:                    yearsH1:                    years Based on the hypotheses, find the following: Test Statistic z =  (Give answer to at least 4 decimal places)p-value = (Give answer to at least 4 decimal places) Based on the above we choose to       The correct summary would be:       that the claim that the mean age smokers first start is different than 13.

The mean age when smokers first start is 13 years old with a population standard deviation of 1.8 years. A researcher thinks that smoking age has significantly changed since the invention of ENDS—electronic nicotine delivery systems. A survey of smokers of this generation was done to see if the mean age has changed. The sample of 30 smokers found that their mean starting age was 12.2 years old. Do the data support the claim at the 10% significance level? What are the correct hypotheses? H0:                    yearsH1:                    years Based on the hypotheses, find the following: Test Statistic z =  (Give answer to at least 4 decimal places)Critical Values =±  (Give answer to at least 4 decimal places) Based on the above we choose to      The correct summary would be:       that the claim that the mean age smokers first start is different than 13.

The Insure.com website reports that the mean annual premium for automobile insurance in the United States was $1,503 in March 2014. Being from Pennsylvania at that time, you believed automobile insurance was cheaper there and decided to develop statistical support for your opinion. A sample of 25 automobile insurance policies from the state of Pennsylvania showed a mean annual premium of $1,430 with a standard deviation of s = $160. (a) Develop a hypothesis test that can be used to determine whether the mean annual premium in Pennsylvania is lower than the national mean annual O Ho: u = 1,503 H: u # 1,503 premium. o Ho: H 1,503 O Ho: H > 1,503 Ha:uS 1,503 (b) What is a point estimate in dollars of the difference between the mean annual premium in Pennsylvania and the national mean? (Use the mean annual premium in Pennsylvania minus the national mean.)

The mean age when smokers first start is 13 years old with a population standard deviation of 1.9 years. A researcher thinks that smoking age has significantly changed since the invention of ENDS—electronic nicotine delivery systems. A survey of smokers of this generation was done to see if the mean age has changed. The sample of 32 smokers found that their mean starting age was 12.4 years old. Do the data support the claim at the 1% significance level? What are the correct hypotheses? H0:                    yearsH1:                    years Based on the hypotheses, find the following: Test Statistic z = ________ (Give answer to at least 4 decimal places)Critical Values =± _______  (Give answer to at least 4 decimal places) Based on the above we choose to   ____________   The correct summary would be: _________  that the claim that the mean age smokers first start is different than 13.

The mean age when smokers first start is 13 years old with a population standard deviation of 1.8 years. A researcher thinks that smoking age has significantly changed since the invention of ENDS—electronic nicotine delivery systems. A survey of smokers of this generation was done to see if the mean age has changed. The sample of 33 smokers found that their mean starting age was 12.3 years old. Do the data support the claim at the 5% significance level? What are the correct hypotheses?   Based on the hypotheses, find the following: Test Statistic z =   (Give answer to at least 2 decimal places) From the table(https://ma336.qccmathcs.com/ ), Find p-value =   (Give answer to at least 4 decimal places)

The mean age when smokers first start is 13 years old with a population standard deviation of 1.8 years. A researcher thinks that smoking age has significantly changed since the invention of ENDS—electronic nicotine delivery systems. A survey of smokers of this generation was done to see if the mean age has changed. The sample of 32 smokers found that their mean starting age was 12.4 years old. Do the data support the claim at the 1% significance level? What are the correct hypotheses? H0: Select an answer s² s p̂ x̄ σ p σ² μ  ? ≥ = > ≠ < ≤   yearsH1: Select an answer p s s² σ² μ σ p̂ x̄  ? ≤ = ≥ < ≠ >   years Based on the hypotheses, find the following: Test Statistic z =  (Give answer to at least 4 decimal places)Critical Values =±±  (Give answer to at least 4 decimal places) Based on the above we choose to Select an answer Accept the null hypothesis Accept the alternative hypotheis Fail to reject the null hypothesis Reject the null hypothesis  The correct summary would…

Given that the researcher wants to be sure the mean difference in the change in hemoglobin levels has a margin of error no more than 0.2 g/dL and the difference in the stand deviation between the mean hemoglobin levels for the two forms of iron supplements used to treat anemia is 1.2 g/dL, what is the desired number of recruits for the study, assuming the individuals will participate in a crossover trial, if the study’s attrition rate is expected to be .25? Group of answer choices n= 139 n= 186 n= 554 n= 55,320

a Leche League International reports that the mean age of weaning a child from breastfeeding is age four to five worldwide. In America, most nursing mothers wean their children much earlier. Suppose a random survey is conducted of 21 U.S. mothers who recently weaned their children. The mean weaning age was 9 months (3/4 year) with a standard deviation of 2 months. Conduct a hypothesis test to determine if the mean weaning age in the U.S. is less than four years old. Conduct a hypothesis test at the 5% level. a. What is the p-value? (Round your answer to four decimal places.) b. What is the test statistic