A medical research team wanted to perform a statistical inference procedure to see if there is a difference in the proportion of people that report headache pain relief within 30 minutes of taking either acetaminophen or ibuprofen. Volunteers that suffer from regular headaches were split into tu groups: one who took acetaminophen at the onset of a headache and one group that took ibuprofen The proportion of those that reported relief within 30 minutes were counted and a 95% confidence interval for the true difference in proportion of pain relief was calculated. The interval was (-0.125, 0.083). Does this interval show evidence that there is a difference between the two medications? No; without knowing the sample size, no conclusion can be made. В No; since o is included in the interval, there is no evidence of a difference. C Yes; since o is included in the interval, there is proof of a difference. Yes; the interval shows that there is a difference since the values are more than 5%.

Ms. Rains believes more seniors from PLD plan to attend college than seniors at Lafayette. In a random sample of 35 PLD seniors, 21 responded they plan to attend college. In a random sample of 32 Lafayette seniors only 17 responded they plan to attend college. Using a 95% confidence interval, predict the true difference in the proportion of seniors at PLD and Lafayette who plan to attend college and comment on Ms. Rains' belief.

A marketing study with a random sample of 400 results in 160 subjects reacting positively to the proposed product. Determine the 95% confidence interval for the population proportion.

Among 1815 randomly selected high school students surveyed by the Centers for Diseases Control, 300 said they were current smokers. d. Interpret the 95% confidence interval in this context.

A recent provincial report states that 90% of the population is aware that piercings as well as tattoos can transmit infectious disease. A survey was conducted in the province and random subjects were asked if they knew that piercings as well as tattoos could transmit an infectious disease. Following this,  1450 people responded  with "yes" and 48 responded with "no".  Find the 95% confidence interval estimate of the proportion of those who know that  piercings as well as tattoos can transmit an infectious disease.

A sports news station wanted to know whether people who live in the North or the South are bigger sports fans. For its study, 121 randomly selected Southerners were surveyed and found to watch a mean of 4.6 hours of sports per week. In the North, 176 randomly selected people were surveyed and found to watch a mean of 3.2 hours of sports per week. Find a 90% confidence interval for the true difference between the mean numbers of hours of sports watched per week for the two regions if the South has a population standard deviation of 1.6 hours per week and the North has a population standard deviation of 1.4 hours per week. Let Population 1 be people who live in the South and Population 2 be people who live in the North. Round the endpoints of the interval to one decimal place, if necessary. Lower endpoint: Upper endpoint:

According to the website www.collegedrinkingprevention.gov, "About 25 percent of college students report academic consequences of their drinking including missing class, falling behind, doing poorly on exams or papers, and receiving lower grades overall." A statistics student is curious about drinking habits of students at his college. He wants to estimate the mean number of alcoholic drinks consumed each week by students at his college. He plans to use a 90% confidence interval. He surveys a random sample of 63 students. The sample mean is 3.7 alcoholic drinks per week. The sample standard deviation is 3.2 drinks. Construct the 90% confidence interval to estimate the average number of alcoholic drinks consumed each week by students at this college. 1. The t value is - 2. The standard error has a value of -- 3. The margin of error has a value of 4. Construct the 90% confidence interval to estimate the average number of alcoholic drinks consumed each week by students at this college.

What is the power of a study using a correlation, with a one-tailed test at the .05 significance level, in which the researchers predict a large effect size and there are 50 participants? How many participants do you need for 80% power in a planned study in which you predict a small effect size and will be using a correlation, one-tailed, at the .05 significance level?

University personnel are concerned about the sleeping habits of students and the negative impact on academic performance.  In a random sample of 377 U.S. college students, 209 students reported experiencing excessive daytime sleepiness (EDS).  Is there sufficient evidence to conclude that more than half of U.S. college students experience EDS?  Use a 5% level of significance. What is a 90% confidence interval estimate for the proportion of all of U.S. college students who experience excessive daytime sleepiness? PLAN: State the name of the appropriate estimation procedure (e.g. one-sample t confidence interval for estimating the mean difference).  You have already listed the conditions, now check the condition for the normality of the sampling distribution of p-hat for confidence interval estimation

A poll showed that 40 out of 200 randomly chosen graduates of California medical schools last year intended to specialize in family practice. What is the width of a 95 percent confidence interval for the proportion that plan to specialize in family practice?