Embry Riddle wants to know more about the knowledge of their

Embry Riddle wants to know more about the knowledge of their Graduate students regarding international Aviation law. They are concerned that their students are uninformed in regards to international law from other countries. A standardized test is used to assess the students knowledge (national reported mean=65, sd=5). A sample of 30 students are tested (sample mean=58, standard error=3.2). Compute a 99 percent confidence interval based on this sample\'s data. How do these students compare to the national sample?

Solution

Given a=0.01, Z(0.005) = 2.58 (from standard normal table)

So 99 percent confidence interval based on this sample\'s data is

xbar +/- Z*s/vn

-->58 +/- 2.58*3.2

--> (49.744, 66.256)

Since the interval includes 65, there is not significant different between national reported and sample data.