Question

A study finds that graduate students send a mean of 74 text messages per day with a standard deviation of 15.2 text message per day while undergraduate students send a mean of 116 text messages per day with a standard deviation of 26.51. Which group, the undergraduate students or the graduate students have more variation in the number of sent text messages?

		Undergraduates, because their standard deviation is higher
		Undergraduates, because their standard deviation is lower
		Graduate students, because their standard deviation is higher
		Graduate students, because their standard deviation is lower

Lenny is an elementary school principal. He's concerned about how the families at his school are doing currently, so he creates a list of questions to ask some of them to get an idea of how they're holding up.

Match each scenario below with the correct sampling technique.

He makes a numbered list of every family's contact information in the school. Then he has a random number generator select 50 of them for him to call. He asks every one of the teachers at his school to randomly select 5 students' families to contact. He makes a numbered list of every family's contact information in the school. He chooses a random number to start with, then picks every 10th family on the list to call. He contacts the parents that are typically involved and that he generally speaks with on a regular basis because he knows they're easy to talk to. He makes a list of every family's contact information in the school and sends an e-mail survey out to all of them, or a hard copy to those without e-mail information.

A.	systematic sample
B.	stratified sample
C.	simple random sample
D.	that's actually the population
E.	convenience sample

Answer 1