researcher examines whether an over-the-counter cold medication influences mental alertness of prison wardens. A random sample of n = 16 participants is obtained, and each person is given a standard dose of the medication one hour before being tested on a simulation task. For the general population, scores on the simulation task are normally distributed with µ = 60 and σ = 8. The individuals in the

he data on the number of chocolate chips per bag for 42 bags of Chips Ahoy! cookies were obtained by the students in an introductory statistics class at the United States Air Force Academy in response to the Chips Ahoy! 1,000 Chips Challenge sponsored by Nabisco, the makers of Chips Ahoy! Use the data collected by the students to answer the following questions and to conduct the analyses required in each part. They found ¯xx¯ = 1261.6 and s = 117.6 a. Determine a 95% confidence interval for the mean number of chips per bag for all bags of Chips Ahoy! cookies. ≤μ≤≤μ≤  b. Interpret your result in words.    c. Can you conclude that the average bag of Chips Ahoy! Cookies contain at least 1000 chocolate chips?    yes no

A researcher studying air quality in a metropolitan city is interested in testing the claim that less than 20% of people smoke cigarettes to test this claim the researcher collects the following data on a sample of 700 adults and 110 of them smoke cigarettes the following is the data from the study. Sample size= 700 adults Alternative hypothesis= ha:p

Bighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 15.8 17.3 14.4 19.6 20.0   Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1,540.45; Σxy = 272 (a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to three decimal places.) x =  y =  b =  ŷ =  +  x (b) Draw a scatter diagram for the data. Plot the least-squares line on your scatter diagram.         (c) Find the sample correlation coefficient r and the coefficient of determination r2. (Round your answers to three decimal places.) r =   r2 =   What percentage of variation in y is…

Bighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 13.8 19.3 14.4 19.6 20.0 Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1554.45; Σxy = 274b) Find the equation of the least-squares line. (Round your answers to two decimal places.) ŷ =  +  x (c) Find r. Find the coefficient of determination r2. (Round your answers to three decimal places.) r =   r2 =     d) Test the claim that the population correlation coefficient is positive at the 1% level of significance. (Round your test statistic to three decimal places.) t =

College students and STDs: A recent report estimated that 25% of all college students in the United States have a sexually transmitted disease (STD). Due to the demographics of the community, the director of the campus health center believes that the proportion of students who have a STD is higher at his college. He tests H0: p = 0.25 versus Ha: p > 0.25. The campus health center staff select a random sample of 150 students and determine that 43 have been diagnosed with a STD. Conduct a hypothesis test to address the director’s hypothesis. Use a 5% significance level to make your decision. Use the applet to determine the P‑value. Click here to open the applet. Which of the following is an appropriate conclusion based on the results?  The data provides strong evidence that the proportion of students at his college who have a STD is more than 25%.  The data suggests that the proportion of students at his college who have a STD is 29%.  Of the students surveyed at his college, 29%…

(OPHTHALMOLOGY) The following data are from a study on Botox injections. Patients received a high-dose injection in one eye (experimental treatment = treatment E) and a low-dose injection in the other eye (control treatment = treatment C). Patients were asked to rate the level of pain in each eye on a 1–10 scale, with higher scores indicating more pain. The assignment of treatments to eyes was randomized. The subjects came back over several visits. Data from the last visit are given in the following table:  1. Which of the following is the correct test to conduct given the situation above? 2. The hypotheses are: 3. What is the level of significance? 4. What is the computed test statistic? Hint: Use (mean of "Pain in E eye") minus (mean of "Pain in C eye") 5. What is the correct decision based on the p-value or critical value method?

Bighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 15.8 17.3 14.4 19.6 20.0   Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1,540.45; Σxy = 272 (a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to three decimal places.) x =   y =   b =   ŷ =   +   x

Denny studied factors affecting cardiovascular reactivity to a postural change in a sample of healthy men and women. Change in systolic blood pressure (SBP) from supine to standing position was used as the measure of cardiac reactivity in a sample of 842 adults. Supine measurement of blood pressure was taken after participants had lain on an examination table for 15 minutes. Blood pressure was determined every 30 seconds using a Dinamap device for 2 minutes, and the measurements were averaged. Participants then stood up immediately, and additional measurements were made for another 2 minutes. Below is a table describing the characteristics of Denny’s sample: Which measures of dispersion, if any, are presented in this table (Ranges, SDs)? If age is normally distributed, approximately what percent of the sample would be younger than 50? If BMI is normally distributed, approximately what percent of the sample would have a BMI higher than 33.1?

Prices of diamonds are very sensitive to their weight (measured in carat). For example, the price of a 1 carat diamond tends to be much higher than the price of a 0.99 carats diamond. To study this phenomenon in more detail, we consider two random samples of diamonds, 0.99 carats and 1 carat, each sample of size 23. The average price of 0.99 carats diamonds in the sample is $4451, while the average price of 1 carat diamonds in the sample is $5681. From long-term studies, we know that both the prices of 0.99 carats diamonds and the prices of 1 carat diamonds are normally distributed with standard deviations oj = $1332 (0.99 carats) and o2 = $1613 (1 carat), respectively. (a) Carry out a hypothesis test at significance level 0.01 to evaluate whether the true average price µi of 0.99 carats diamonds is lower than the true average price µ2 of 1 carat diamonds. Specify Ho and Ha, the test statistic, and calculate the p-value or use p-value considerations to conclude. (b) Compute the type II…