The group of students had a test on Statistics. The following student’s blood pressure results are given in the table before and after the test:  Student 1 2 3 4 5 6 7 8 before 70 74 73 80 74 85 81 75 after 72 78 75 79 84 88 82 78 а) Find 95% confidence interval for the μd - difference of the student’s blood pressure results before and after the test, b) Do the data support that the blood pressure is changed at the α=0.05? The difference is believed to be approximately normally distributed.

The accompanying data were read from a plot (and are a subset of the complete data set) given in an article. The data represent the mean response times for a group of individuals with closed-head injury (CHI) and a matched control group without head injury on 10 different tasks. Each observation was based on a different study, and used different subjects, so it is reasonable to assume that the observations are independent. Study 1 y= 2 3 4 5 6 7 8 9 10 Mean Response Time CHI Control 250 360 475 525 610 740 880 920 1010 1200 304 492 432 659 683 922 1044 1421 1329 1481 1815 (a) Fit a linear regression model that would allow you to predict the mean response time for those suffering a closed-head injury from the mean response time on the same task for individuals with no head injury. (Round your answers to four decimal places.) (b) Do the sample data support the hypothesis that there is a useful linear relationship between the mean response time for individuals with no head injury and the…

Students in an experimental psychology class did research on depression as a sign of stress. A test was administered to a sample of 30 students. The scores are given. Complete parts (a) through (c) below. 32 54 11 15 35 21 OA. 158 34 15 55 51 11 35 2 1457 3 1234567 4123445566 511245666 34 33 46 OB. 11155 (a) Find the mean and median of the data. The mean is . (Round to three decimal places as needed.) 44 26 27 The median is .(Type an integer or a decimal.) (b) Draw a stem-and-leaf plot for the data using one row per stem. Which stem-and-leaf plot below shows the data? 2 112677 3 233445556 4 244666 5 1456 ... 21 42 38 OA. The distribution is symmetric. B. The distribution is skewed right (positively skewed). OC. The distribution is skewed left (negatively skewed). O D. The distribution is uniform. (c) Describe the shape of the distribution. Which description below best describes the shape of the distribution? 56 46 OC. 1112455668 2 14556 3 15 4 13457 5 223446667 46 27 33 35 22 44 36 0…

An experiment was conducted to determine if exposure to an advertisement would change attitude toward a product. Each subject’s attitude before and after exposure to the advertisement was recorded, using a valid ten point scale. The results indicated: Subject Attitude Post Exposure Attitude Pre Exposure   1 6 4 2 8 5 3 6 6 4 4 3 5 7 2 6 6 3 7 9 6 8 7 6 9 8 5 10 8 6   Set up hypotheses and test to determine if the mean attitude toward the product increased as a result of exposure to the advertisement. (Note: these samples must be regarded as dependent, as each subject served as both a control (pre-exposure) and a treatment (post exposure).   Fully interpret your result.