Hi I need help on what us the answer for this activity. Below is the problem and answer with explanation is recommended. I hope that you can help me and surely I will give you full positive feedbacks
Significance level? 2. Arsenic concentration in public drinking water supplies is a potential health risk. A journal article reported that drinking water arsenic concentrations in parts per billion (ppb) for 10 metropolitan communities and 10 rural communities. We wish to determine whether mean arsenic concentration for metropolitan communities is lower than the mean arsenic concentration for rural communities. The data follow: Sample Standard Community Sample Mean Deviation Metropolitan 15.5 8.52 Rural 28.5 14.31 Assume that the two population variances are not equal, . Test the hypothesis at level of significance. 3. Twelve adult males between the ages of 35 and 50 participated in a study to evaluate the effect of diet and exercise on blood cholesterol levels. The total cholesterol was measured in each subject initially and then three months after participating in an aerobic exercise program and switching to a low-fat diet. The data on the blood cholesterol levels are shown in the following table. Do the data support the claim that low-fat diet and aerobic exercise are of value in producing a mean reduction in blood cholesterol levels? Use a = 0.05. Subject 1 2 3 4 5 6 7 8 9 10 11 12 Before 265 240 258 295 251 245 287 314 260 279 283 240 After 229 231 227 240 238 241 234 256 247 239 246 218 4. A cigarette manufacturer wishes to test the claim that the variance of the nicotine content of its cigarettes is 0.644. Nicotine content is measured in milligrams, and assume that it is normally distributed. A sample of 20 cigarettes has a standard deviation of 1.00 milligram. At , is there enough evidence to reject the manufacturer's claim? 5. A study is conducted to compare the length of time between men and women to assemble a certain product. Past experience indicates that the distribution of times for both men and women is approximately normal but the variance of the times for women is less than that for men. A random sample of times for 11 men and 14 women produced the following data: Men Women Using a 5% level of significance, test the hypothesis that against the alternative that .Instructions: Answer the following problem as indicated. Follow the steps in hypothesis testing like what was presented in the leaming guides. Each step has equivalent points. Write your answers neatly and systematically. 1. A manufacturer of sprinkler systems used for fire protection in office buildings claims that the true average system-activation temperature is 131*F. A sample of 12 systems, when tested, yields a sample average activation temperature of 132 01"F with standard deviation of 1.9"F. If the distribution of activation times is normal, does the data contradict the manufacturer's claim at 1% significance level? 2. Arsenic concentration in public drinking water supplies is a potential health risk. A journal article reported that drinking water arsenic concentrations in parts per billion (ppb) for 10 metropolitan communities and 10 rural communities. We wish to determine whether mean arsenic concentration for metropolitan communities is lower than the mean arsenic concentration for rural communities. The data follow: Sample Standard Community Sample Meart Deviation Metropolitan 156 Rum 28 5 14 31 Assume that the two population variances are not equal, . Test the hypothesis at level of significance. 3. Twelve adult males between the ages of 35 and 50 participated in a study to evaluate the effect of diet and exercise on blood cholesterol levels. The total cholesterol Was measured in each subject initially and then three months after participating in an aerobic exercise program and switching to a low-fat diet. The data on the blood cholesterol levels are shown in the following table. Do the data support the claim that low-fat diet and aerobic exercise are of value in producing a mean reduction in
