21.6 Are students engaged in school? Results from a summer 2010 Gallup

Student Survey reveal that 37% of students in the 5th through 12th grades feel

either not engaged or actively disengaged in school. The report of this sample

survey of 642 students aged 10 to 18 stated that, with 95% confidence, the margin

of sampling error was ±4.94%. Explain to someone who knows no statistics what

the phrase “95% confidence” means in this report.

If we do so many repeated samples, we are guaranteed that only 95% of all

intervals that are constructed will contain the true population parameter.