Login
Premium
Home Question Bank Math Statistics Archive 2024 November 24

Statistics Questions from Nov 24,2024

Browse the Statistics Q&A Archive for Nov 24,2024, featuring a collection of homework questions and answers from this day. Find detailed solutions to enhance your understanding.

error msg
The file a4data. RData contains the two data frames q1 and q2 to be used for this assignment. 1. [12 marks] A researcher was interested in studying the effectiveness on smoking cessation of a nicotine patch, bupropion SR or both, when co-administered with cognitive-behavioural therapy. Subjects assigned themselves to one of nicotine patch (NTP), bupropion SR (B) or both (BNTP). At study initiation each subject's smoking history, measured by pack years was estimated. The q1 data frame contains the pack years (YEARS) and treatment (GROUP) for these subjects. (a) Investigate whether or not the pack years were comparable among the groups. In other words, perform the appropriate analysis including a suitable plot of the data. If there are differences, which group(s) appear to differ. (b) Considering the goal of the research study, are there problems evident with the study design? If so, how could it be improved? [20 marks] The q2 data frame contains INR measures by two different methods. The X variable contains the result of the standard measurement while Y contains the result of a new measurement. We wish to see if Y can be predicted by X. Perform an analysis that describes the relationship between the two measures, including a suitable plot. Your analysis should test whether or not there is any relationship between the two measurements. You should assess the assumptions of your analysis. BONUS: [ 2 marks] In studies of this sort the question is often more specific than looking for an association. The real interest is in if the measurements are the same. This is a more involved problem but one consequence is that if the measurements are expected to agree, the slope of the regression line would be expected to be equal to 1 . Do you find the data to be consistent with a slope of 1 ? Explain your reasoning including how you are defining "consistent." f) \( \binom{15}{3}= \) nder the Weibull model for mortality, the survival function is of the form: \[ S_{x}(t)=\exp \left(-\alpha t^{\beta}\right) \] here \( \alpha, \beta>0 \). Derive an expression in terms of \( \alpha \) and \( \beta \) for \( \mu_{x+t} \) under this model. Determine an expression involving \( \alpha \) for \( E\left(T_{x}\right) \) in the case when \( \beta=1 \). An experiment involving peas results in 580 offspring, 152 of which peas have yellow pods. Mendel claimed that the proportion of peas with yellow pods should be \( 25 \% \). We want to know if these data are consistent with Mendel's hypothesis. Which statistical inference procedures should we use? one-sample \( t \) test two-sample \( t \) test chi-square test for goodness of fit chi-square test for two-way table A study finds that a simple random sample of 57 butterflies captured in a given natural habitat is made up of 12 blue, 19 yellow, and 26 white butterflies. We want to know if this is significant evidence that blue, yellow, and white butterflies are not equally represented in the habitat's population of butterflies. What is the value of the chi-square statistic for this test, approximately? 0.08 2.57 0.33 5.16 b. Find the equation of the regression line for the percentage of teenagers who have used Drug 1 and the percentage who have used other drugs. \( y=\square \mathrm{x}+(\square) \) (Round to two decimal places as needed.) A research article described a simple random sample of 584 smokers who tried to quit smoking by using either a nicotine patch or e-cigarettes, fake cigarettes producing nicotine in water vapor form. After six months, \( 7.3 \% \) of those using e-cigarettes had stopped smoking, compared with \( 5.8 \% \) of those wearing the patch. To see if quitting result is significantly associated with the method used, which statistical inference procedure should we use? matched pairs \( t \) test two-sample \( t \) test chi-square test for goodness of fit chi-square test for two-way table 5. A psychologist is interested in exploring the effect of tutorial support on students' academic performance and assign students into two groups. Students in group one get the tutorial support and those in group two do not. In this example, what is the a) Dependent variable b) Independent variable c) Control group d) Experimental group Researchers selected a simple random sample of 4048 medical records of adults diagnosed with gum disease. In all, 2226 were current smokers, 891 were former smokers, and 931 never smoked regularly. Their research question is: Do these data indicate that gum disease is equally likely regardless of smoking status? What is the chi-square statistic for the null hypothesis of an equal representation of current, former, and never smokers among adults diagnosed with gum disease? 4048 1349.33 854.95 \( 1 / 3 \)
Prev 1 2 3 4 5 6
...
17 Next
1 2 3 4 5 6
...
17
Prev Next
Study can be a real struggle
Why not UpStudy it?
Select your plan below
Premium

You can enjoy

Start now
  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to Answer and Solution
  • Full Access to PDF Chat, UpStudy Chat, Browsing Chat
Basic

Totally free but limited

  • Limited Solution
Welcome to UpStudy!
Please sign in to continue the Thoth AI Chat journey
Continue with Email
Or continue with
By clicking “Sign in”, you agree to our Terms of Use & Privacy Policy