A researcher believes that more sleep can result in better reaction time. A random sample of adults were involved in the study, where the amount of sleep they got the previous night was recorded and their reaction time was measured the next morning using a standard test for reaction time . The data is given in the table below. At the alpha = 0.05 level of significance , test the researcher's claim that there is a negative linear correlation between sleep and reaction time. Round all results to three decimal places .

It has been found that 25.1% of men (Group 1) 20 years and older suffer from hypertension (high blood pressure) and 33.9% of women (Group 2) are hypertensive. A random sample of 164 of each gender was selected from recent hospital records, and the following results were obtained. Can you conclude that a higher percentage of women have high blood pressure? Use =0.05. Men: 42 patients had high blood pressure Women: 52 patients had high blood pressure   Required: Test Value Only the final answer should be rounded-off to TWO decimal places.

Child Health and Development Studies (CHDS) has been collecting data about expectant mothers in Oakland, CA since 1959. One of the measurements taken by CHDS is the weight increase (in pounds) for expectant mothers in the second trimester. In a fictitious study, suppose that CHDS finds the average weight increase in the second trimester is 14 pounds. Suppose also that, in 2015, a random sample of 40 expectant mothers have mean weight increase of 15.8 pounds in the second trimester, with a standard deviation of 6.2 pounds. A hypothesis test is done to see if there is evidence that weight increase in the second trimester is greater than 14 pounds. Find the p-value for the hypothesis test.  The p-value should be rounded to 4 decimal places.

Suppose an experiment finds that people taking a new herbal remedy get fewer colds than people taking a placebo.  The results are statistically significant at the 0.01 level.  Has the experiment proven that the herbal remedy works?

A researcher conducts a between-subjects study to determine whether low levels of the neurochemical serotonin leads to an increase in aggression. One sample of rats serves as a control group and receives a placebo that does not affect normal levels of serotonin. A second sample of rats receives a drug that lowers brain levels of serotonin. Using an alpha level of a = .05, the researcher then tests the animals by recording the number of aggressive responses each of the rats display. The data are as follows: a.) Step 1: State the Hypotheses Ho: H₁: Control n = 10 M = 14 SS=180.5 b.) Step 2: Determine the critical region and draw it on the distribution above: df = > *critical SM₁-M₂ Low Serotonin n = 15 M = 19 SS = 130.0 c.) Step 3: Calculate the test statistic using the provided sample data: tobs d.) Step 4: Make a decision. Circle one: Reject Null (Ho) or Fail to Reject Null (Ho) e.) State your conclusions about the research scenario in sentence form: d= f.) What is the estimated effect…

An exercise scientist wants to know if there is a relationship between explosive leg power and standing jump height.  To determine if a relationship exists, a group of 30 participants' (N = 30) Leg power was measured  by recording each participants' single squat weight max (in pounds). Next, each participant was asked to perform a standing jump and their Jump height was recorded (in meters). Using the variables “Leg power” and “Jump height”, conduct a Pearson's Correlation, at α = 0.05, to determine if leg power and jump height are correlated   Interpret r. What type of correlation exists between leg strength and jump height?   A. A negative correlation B. No correlation C. A positive correlation D. We cannot know based on the available information

Researchers have noted a decline in cognitive functioning as people age (Bartus, 1990). However, the results from other research suggest that the antioxidants in foods such as blueberries may reduce and even reverse these age-related declines (Joseph et al., 1999). To examine this phenomenon, suppose that a researcher obtains a sample of n = 16 adults who are between the ages of 65 and 75. The researcher uses a standardized test to measure cognitive performance for each individual. The participants then begin a 2-month program in which they receive daily doses of a blueberry supplement. At the end of the 2-month period, the researcher again measures cognitive performance for each participant. The results show an average increase in performance of MD = 7.4 with SS = 1215. Does this result support the conclusion that the antioxidant supplement has a significant effect on cognitive performance? Use a two-tailed test with α = .05. Show your computations.

A team of epidemiologists at the Mayo Clinic wanted to find whether there is an association between obesity and cardiovascular disease (CVD). They conducted a prospective cohort study following obese and non-obese individuals who were free of CVD at the beginning of study for five years. The investigators were also interested in assessing age as a potential confounder, effect modifier, or both. Use the data below to answer the accompanying questions.     CVD No CVD Total Obese 10 90 100 Not Obese 35 465 500 Total 45 555 600       CVD No CVD Total Obese 36 164 200 Not Obese 25 175 200 Total 61 339 400   1. Compute the appropriate measure of association for those who were less than age 50.  2. Compute the appropriate measure of association for those who were older or equal to age 50.  3. Compute the crude measure of association?  4. List three attributes that age must satisfy before it could…

A study was conducted of 90 adult male patients following a new treatment for congestive heart failure. One of the variables measured on the patients was the increase in exercise capacity (in minutes) over a 4-week treatment The previous treatment regime had produced an average increase of μ = 2 minutes. The researchers wanted to evaluate whether the new treatment had increased the value of μ in comparison to the previous treatment. The sample data yielded ?̅ = 2.17 and ? = 1.05: Using α = 05, what conclusions can you draw about the research hypothesis?