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Dietary Improvement and Depression In a 2017 study, researchers investigated the effect of dietary improvement on adults with moderate to severe depression (Jacka et al. 2017). Subjects were randomly assigned to a treatment group consisting of seven individual nutritional consulting sessions with a clinical dietician or a control condition consisting of a social support protocol with the same visit schedule and length as the treatment group. There were 33 subjects in the treatment group and 34 subjects in the control group. Remission from depression symptoms was achieved by 10 subjects in the treatment group and 2 subjects in the control group.
a. Was this an observational study or a controlled experiment? Explain.
b. Find the percentage in each group that achieved remission from depression symptoms.
c. Researchers performed a test to determine if there was significant difference in outcomes between the treatment and control groups. The
i. Researchers have shown that dietary improvement may be an effective treatment strategy for patients with moderate to severe depression.
ii. Researchers have not shown that dietary improvement may be an effective treatment strategy for patients with moderate to severe depression.
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Chapter 12 Solutions
Introductory Statistics Plus Mylab Statistics With Pearson Etext -- Access Card Package (3rd Edition)
- Exercise 6-6 (Algo) (LO6-3) The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience. Admissions Probability 1,100 0.5 1,400 0.4 1,300 0.1 Click here for the Excel Data File Required: What is the expected number of admissions for the fall semester? Compute the variance and the standard deviation of the number of admissions. Note: Round your standard deviation to 2 decimal places.arrow_forward1. Find the mean of the x-values (x-bar) and the mean of the y-values (y-bar) and write/label each here: 2. Label the second row in the table using proper notation; then, complete the table. In the fifth and sixth columns, show the 'products' of what you're multiplying, as well as the answers. X y x minus x-bar y minus y-bar (x minus x-bar)(y minus y-bar) (x minus x-bar)^2 xy 16 20 34 4-2 5 2 3. Write the sums that represents Sxx and Sxy in the table, at the bottom of their respective columns. 4. Find the slope of the Regression line: bi = (simplify your answer) 5. Find the y-intercept of the Regression line, and then write the equation of the Regression line. Show your work. Then, BOX your final answer. Express your line as "y-hat equals...arrow_forwardApply STATA commands & submit the output for each question only when indicated below i. Generate the log of birthweight and family income of children. Name these new variables Ibwght & Ifaminc. Include the output of this code. ii. Apply the command sum with the detail option to the variable faminc. Note: you should find the 25th percentile value, the 50th percentile and the 75th percentile value of faminc from the output - you will need it to answer the next question Include the output of this code. iii. iv. Use the output from part ii of this question to Generate a variable called "high_faminc" that takes a value 1 if faminc is less than or equal to the 25th percentile, it takes the value 2 if faminc is greater than 25th percentile but less than or equal to the 50th percentile, it takes the value 3 if faminc is greater than 50th percentile but less than or equal to the 75th percentile, it takes the value 4 if faminc is greater than the 75th percentile. Include the outcome of this code…arrow_forward
- solve this on paperarrow_forwardApply STATA commands & submit the output for each question only when indicated below i. Apply the command egen to create a variable called "wyd" which is the rowtotal function on variables bwght & faminc. ii. Apply the list command for the first 10 observations to show that the code in part i worked. Include the outcome of this code iii. Apply the egen command to create a new variable called "bwghtsum" using the sum function on variable bwght by the variable high_faminc (Note: need to apply the bysort' statement) iv. Apply the "by high_faminc" statement to find the V. descriptive statistics of bwght and bwghtsum Include the output of this code. Why is there a difference between the standard deviations of bwght and bwghtsum from part iv of this question?arrow_forwardAccording to a health information website, the distribution of adults’ diastolic blood pressure (in millimeters of mercury, mmHg) can be modeled by a normal distribution with mean 70 mmHg and standard deviation 20 mmHg. b. Above what diastolic pressure would classify someone in the highest 1% of blood pressures? Show all calculations used.arrow_forward
- Write STATA codes which will generate the outcomes in the questions & submit the output for each question only when indicated below i. ii. iii. iv. V. Write a code which will allow STATA to go to your favorite folder to access your files. Load the birthweight1.dta dataset from your favorite folder and save it under a different filename to protect data integrity. Call the new dataset babywt.dta (make sure to use the replace option). Verify that it contains 2,998 observations and 8 variables. Include the output of this code. Are there missing observations for variable(s) for the variables called bwght, faminc, cigs? How would you know? (You may use more than one code to show your answer(s)) Include the output of your code (s). Write the definitions of these variables: bwght, faminc, male, white, motheduc,cigs; which of these variables are categorical? [Hint: use the labels of the variables & the browse command] Who is this dataset about? Who can use this dataset to answer what kind of…arrow_forwardApply STATA commands & submit the output for each question only when indicated below İ. ii. iii. iv. V. Apply the command summarize on variables bwght and faminc. What is the average birthweight of babies and family income of the respondents? Include the output of this code. Apply the tab command on the variable called male. How many of the babies and what share of babies are male? Include the output of this code. Find the summary statistics (i.e. use the sum command) of the variables bwght and faminc if the babies are white. Include the output of this code. Find the summary statistics (i.e. use the sum command) of the variables bwght and faminc if the babies are male but not white. Include the output of this code. Using your answers to previous subparts of this question: What is the difference between the average birthweight of a baby who is male and a baby who is male but not white? What can you say anything about the difference in family income of the babies that are male and male…arrow_forwardA public health researcher is studying the impacts of nudge marketing techniques on shoppers vegetablesarrow_forward
- The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience. Admissions Probability 1,100 0.5 1,400 0.4 1,300 0.1 Click here for the Excel Data File Required: What is the expected number of admissions for the fall semester? Compute the variance and the standard deviation of the number of admissions. Note: Round your standard deviation to 2 decimal places.arrow_forwardA pollster randomly selected four of 10 available people. Required: How many different groups of 4 are possible? What is the probability that a person is a member of a group? Note: Round your answer to 3 decimal places.arrow_forwardWind Mountain is an archaeological study area located in southwestern New Mexico. Potsherds are broken pieces of prehistoric Native American clay vessels. One type of painted ceramic vessel is called Mimbres classic black-on-white. At three different sites the number of such sherds was counted in local dwelling excavations. Test given. Site I Site II Site III 63 19 60 43 34 21 23 49 51 48 11 15 16 46 26 20 31 Find .arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt
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