4. Dr. Sayer is studying how our perceptions of attractiveness have changed over time. He hypothesized that, due to increased concerns over skin cancer, tan skin is perceived as less attractive now than it was 20 years

ago. He compared data from 1987 to current data and found that, on average, tan skin was rated as 4.2 in

attractiveness (on a scale of 1-5, with 5 being most attractive) in 1987 as compared to 3.7 today. In

analyzing these results, what three factors must Dr. Sayer consider when determining if these averages are

reliable?