1. 
   
2. You are a public health nurse working in an elementary school in Hamilton, Ontario. You have seen a substantial increase in the number of children in your school presenting with Attention Deficit Disorder (ADD). You are interested in whether a new drug developed by a local drug company improves the ability of children with ADD to maintain attention. You obtain ethics approval to study the drug, informed consent from the parents of 24 fifth grade children with ADD, administer the drug to the 24 children, and administer a test to the children to determine their ability to maintain attention while performing a task. Scores are continuous, can range from 0 to 25 with higher scores reflecting a better ability to maintain attention, and you know from previous research that scores tend to be normally distributed. Six of these students receive a placebo containing none of the drug. Six students receive 2 mg of the drug, six students receive 4 mg of the drug, and six students receive 6 mg of the drug. The table below summarizes the results from your study. Use these data to answer the following questions. Assume α=0.05.

3. Placebo (0 mg)	Drug (2 mg)	Drug (4 mg)	Drug (6 mg)
   4	7	16	17
   7	8	14	18
   11	13	12	13
   11	6	11	17
   7	9	15	20
   10	9	13	15

4. a.You have one further prediction, and that is that children with ADD who receive the drug will perform significantly better than children with ADD who do not receive the drug. Conduct the appropriate test to confirm this prediction, if the results from question a support doing this additional testing. Are you able to confirm your prediction? Explain, including the calculations and/or SPSS output to support your answer. [2 Marks]

Overproduction of uric acid in the body can be an indication of cell breakdown. This may be an advance indication of illness such as gout, leukemia, or lymphoma.† Over a period of months, an adult male patient has taken twelve blood tests for uric acid. The mean concentration was x = 5.35 mg/dl. The distribution of uric acid in healthy adult males can be assumed to be normal, with σ = 1.87 mg/dl.

(a) Find a 95% confidence interval for the population mean concentration of uric acid in this patient's blood. (Round your answers to two decimal places.)

(b) What conditions are necessary for your calculations? (Select all that apply.)

uniform distribution of uric acidn is largenormal distribution of uric acidσ is knownσ is unknown

(c) Give a brief interpretation of your results in the context of this problem.

There is a 5% chance that the confidence interval is one of the intervals containing the population average uric acid level for this patient.There is not enough information to make an interpretation.     The probability that this interval contains the true average uric acid level for this patient is 0.05.The probability that this interval contains the true average uric acid level for this patient is 0.95.There is a 95% chance that the confidence interval is one of the intervals containing the population average uric acid level for this patient.

(d) Find the sample size necessary for a 95% confidence level with maximal error of estimate E = 1.08 for the mean concentration of uric acid in this patient's blood. (Round your answer up to the nearest whole number.)
blood tests

The 90 students in a statistics class are categorized by gender and by the year in school. The numbers are listed in the following table:

Test the null hypothesis that there is no association between the year in school and the gender using a 1% significance level. Be sure to specify the test statistic with degrees of freedom, the P-value or critical value, and your conclusion. Please no computer software answers! Thank you!

At Burnt Mesa Pueblo, archaeological studies have used the method of tree-ring dating in an effort to determine when prehistoric people lived in the pueblo. Wood from several excavations gave a mean of (year) 1239 with a standard deviation of 43 years. The distribution of dates was more or less mound-shaped and symmetrical about the mean. Use the empirical rule to estimate the following.

(a) a range of years centered about the mean in which about 68% of the data (tree-ring dates) will be found
between  and  A.D.

(b) a range of years centered about the mean in which about 95% of the data (tree-ring dates) will be found
between  and  A.D.

(c) a range of years centered about the mean in which almost all the data (tree-ring dates) will be found
between  and  A.D.

Young Professional magazine was developed for a target audience of recent college graduates who are in their first 10 years in a business/professional career. In its two years of publication, the magazine has been fairly successful. Now the publisher is interested in expanding the magazine’s advertising base. Potential advertisers continually ask about the demographics and interests of subscribers to Young Professional. To collect this information, the magazine commissioned a survey to develop a profile of its subscribers. The survey results will be used to help the magazine choose articles of interest and provide advertisers with a profile of subscribers. As a new employee of the magazine, you have been asked to help analyze the survey results which had a sample size of 410. The data is summarized below: Quantitative Variables Mean Standard Deviation Age 30.112 4.024 Household Income $74,460 $34,818 Qualitative Variables Count Broadband Access Yes: 256 Have Children Yes: 219 a. Develop 95% confidence intervals for the mean age and household income of subscribers. b. Develop 95% confidence intervals for the proportion of subscribers who have broadband access at home and the proportion of subscribers who have children. c.Would Young Professional be a good advertising outlet for online brokers?Justify your conclusion with statistical data.please provide detailed solution

For this problem, collect data on any variables of interest (sample size for each group of the two groups n=>30) and perform a two-sided significance test for comparing two independent population means. You can also simulate your own data. Address the following:

a. A brief introductory paragraph describing the problem. Remember that you want to think of an experiment where you’re comparing 2 independent groups, such as, for example, “the population mean speed for runners using training method A versus runners using training method B.” There is a clinical trial of a drug that is supposed to significantly reduce you cholesterol and the two groups

b. Set up your framework in a null and alternative hypothesis using symbols and notation as they are presented in the textbook. For the null, traditionally should have the general set-up of H0: µ1 = µ2 An example of this could be “µA = the population mean speed for runners using method A is equal to µB = the population mean speed for runners using method B.” H1: can have a <, or >, or ≠ depending on what you choose to test. Using the example above, if you want to test that A is greater than B, then do: H1: µA > µB

c. A paragraph describing how you collected the data (i.e., the number of observations, time of day, etc. Please present the raw data in a table.

d. Create a graph of the means of the two samples using Excel. Clearly label your axes, and give your figure a title.

e. A section explaining the results of the analysis (calculated statistics, and p-values). Based on what you find, state your decision (whether you reject or fail to reject the H0) and conclusion (whether you have sufficient or insufficient evidence for H1).

f. Describe how would you change the experimental design to become dependent or related samples? Think about which factors you could possibly control for that weren’t controlled for in the initial analysis. For example, instead of comparing 2 independent groups of runners using method A vs. B, we could “match” runners across groups according to age, experience, education, height, etc. This approach is more complicated, but worth describing how it could be done.

A survey was conducted to study if parental smoking is associated with the incidence of smoking in children when they reach high school. Randomly chosen high school students were asked whether they smoked and whether at least one of their parents smoked.

The results are summarized in the following table:

Student Smoke Student Don’t

Parents Smoke 262 183

Parents Don’t 120 380

(a) For a randomly selected student in this study, find the conditional probability of smoking given his/her parents smoke.

(b) Suppose we are interested in testing whether parental smoking is independent of children smoking. Which statistical test would you consider for this problem?

(c) (4 points) Write down the R code to carry out that test. You first need to store the data into a matrix.

(d) Calculate the test statistic by yourself.

(e) Write down the R code to obtain the p-value based on your answer in
part(d).
(f) Suppose the p-value is 0.0001, what would be your really world conclusion? (You may use α = 0:05.)

what is the generalizability in the study on maternal health care quality indicator?

A researcher is testing the claim that adults consume an average of at least 1.85 cups of coffee per day. A sample of 35 adults shows a sample mean of 1.70 cups per day with a sample standard deviation of 0.4 cups per day. Test the claim at a 5% level of significance. What is your conclusion?

*Please explain each step, I just don't get it

How do you determine the slope of a line? Is there more than one way to determine the slope? Why or Why not? How do you find the intercepts of a line? Explain using an example.

Salaries of 32 college graduates who took a statistics course in college have a​ mean,x overbarx​,of $ 65,300. Assuming a standard​ deviation,sigmaσ​,of​$13,299​,construct a 95​% confidence interval for estimating the population mean muμ.

​$nothingless than<muμless than<​$nothing

​(Round to the nearest integer as​ needed.)

Should one always select the decision path that has the highest expectation value? Why/Why not? Give an example where one might not.

In the sports industry what types of questions could you ask and assess using linear regression?

Is the bottled water you are drinking really purified water? In a four-year study of bottled water brands conducted by the Natural Resources Defense Council found that 25% of bottled water is just tap water packed in a bottle. Consider a sample of five brands of bottled water and let X equal the number of these brands that use tap water.

1. Explain why X is (approximately) a binomial random variable.

2. Find that the P (x = 2)

3. Find that the P (x <= 1)

4. Calculate the expected value and standard deviation of the distribution.

A sample of 15 measurements, randomly selected from a normally distributed population, resulted in a sample mean, x¯¯¯=6.1 and sample standard deviation s=1.92. Using α=0.1, test the null hypothesis that μ≥6.4 against the alternative hypothesis that μ<6.4 by giving the following.

a) The number of degrees of freedom is: df= .

b) The critical value is: tα= .

c) The test statistic is: ttest=