A random sample of 375 bolts from machine A contained 26 defective bolts, while an independently chosen, random sample of 300 bolts from machine B contained 33 defective bolts. Let p, be the proportion of the population of all bolts from machine A that are defective, and let p, be the proportion of the population of all bolts from machine B that are defective. Find a 90% confidence interval for p, -P. Then find the lower limit and upper limit of the 90% confidence interval. Carry your intermediate computations to at least three decimal places. Round your responses to at least three decimal places. (If necessary, consult a list of formulas.) Lower limit: Upper limit:

A statistical study is made to compare the % of smokers in small rural towns to the overall smoking rate of the US. Of 1500 asults selected randomly from small towns it is found that 285 of them smoke. With a cofidence interval of (017, 0.21). The CDC reports that 15.1% of all American adults smoke. Does the confidence interval suggest that smoking rate is higher in small towns than in the country overall?

A 95% confidence interval was calculated to be (15, 21). This means that if 100 such confidence intervals (CIs) were constructed, then 95% of the CIs will be (15,21) 95% of the CIs will include the population mean The population mean would lie between (15,21) 95 times. The population mean would be found in about 95 of the CIs.

Researchers want to test a new hand exercise plan for arthritis patients to see if they have improved flexibility. They recruited 110 patients with arthritis in their hands and randomly assigned them to one of two treatment groups: group i took their regular medicine and did the new hand exercises; and group 2 only took medicine. After one month, 42 of the 55 in group 1 improved in their flexibility, and 37 of the 55 in group 2 improved their flexibility. Based on the 95% confidence interval (-0.076, 0.258), is there convincing evidence of a difference in the proportion of patients like these who would show improvement in flexibility if they did the new hand exercises along with taking the medicine versus just taking the medicine? v to believe there va difference in the proportion of patients like these who would show improvement in flexibility if they did the new hand exercises along with taking the medicine versus just taking the medicine. Because v contained in the interval, there…

A simple random sample of size n=17 is drawn from a population that is normally distributed. The sample mean is found to be x= 69 and the sample standard deviation is found to be s= 20. Construct a 95% confidence interval about the population mean. ..... The lower bound is The upper bound is