A study examined whether frequent use of digital social media during adolescence is associated with subsequent occurrence of ADHD symptoms. Researchers rated the frequency of digital social media use (high frequency or low frequency of use) of teens who were 15 or 16 years old and did not show symptoms of ADHD at the start of the study. They then followed the participants for two years, and recorded whether or not ADHD symptoms appeared. The results are shown in Table 2.12.

(a) Find p̂₁, the proportion of teens with high frequency of social media use that are diagnosed with ADHD over this two-year period. 

(b) Find p̂₂, the proportion of teens with low frequency of social media use that are diagnosed with ADHD over this two-year period. 

(c) Which group had a higher proportion developing symptoms of ADHD?

(d) Find the difference in proportions, p̂₁ − p̂₂.

(e) What proportion of all the teens in the study developed ADHD? 

(f) Is this an experiment or an observational study? 

(g) Can we conclude that high social media use by teens increases the chance that they will develop ADHD symptoms?

Transcribed Image Text:

Table 2.12 Social Media Use and ADHD Diagnosis Social Media Use ADHD ADHD No ADHD 16 23 39 High frequency Low frequency Total 149 472 621 Total 165 495 660