Week 06 Homework
Distributed: 10/11/2022 Due back in Canvas at 11:59 am ET 10/17/2022
Rubric posted at the end of this document
St. Charles, Ventnor and Reading (2022) examined 267 adults who responded -yes- to a survey item that indicated that they had difficulty swallowing. After a detailed workup, some were classified as being in a -Dysphagia- group, and the remainder were classified as being in a -NoDysphagia- group. All participants were asked about how much social support they experienced surrounding meals and eating. Thus, the two variables in Class06_homework_2022.csv are
(1) Dysphagia Group (Varname = DysphGroup, value -Dysphagia- = yes; value -NoDysphagia- = no
(2) Social support (higher scores indicate more social support)
1. The first question deals with the proportion of true dysphagia adults in the sample.
a. Obtain the frequency count for those who were classified as dysphagic and those who were not.
b. In this population, we would expect 5% of adults to meet sufficient criteria to be dysphagic (.05 is your null hypothesis value). Evaluate the 95% confidence interval of the proportion of dysphagics in your sample, using this null hypothesis value. Summarize what this means, in words.
2. The second question deals with the distribution of the social support variable.
a. Compute the 95% confidence interval of the mean of social support, based on our sample. Again, summarize what this means.
b. Plot a one-group jittered dot plot for social support, showing the distribution of social support. On this graph, superimpose mean social support and the 95% confidence interval of social support (as an error bar).
3. The third question plots and compares social support separately for the two dysphagia groups
a. Plot a two-group jittered dot plot for social support, comparing the distribution of social support in dysphagic and non-dysphagic adults. Again, superimpose the 95% confidence interval of social support in each group as an error bar.
b. Based on your inspection of the means and confidence intervals in each group, what conclusions might you draw as to a test of the null hypothesis that -dysphagic and non dysphagic adults do not differ in social support surrounding meal and eating-? Protip: If you want to see the means/etc. separately for each group, you can use the describeBy function from the psych package