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?

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?

How does an observation about an object differ from an inference about that object

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. which one, if either is correct? a. beryl, because low thermal conductivity results in low heat transfer. b. beryl, because low thermal conductivity results in high heat transfer. d. sapphire, because low thermal conductivity results in high heat transfer. e. neither, because low heat transfer is desirable both in summer and in winter.