In a university class that includes 120 students, mostly non-traditional, the Me

Question

In a university class that includes 120 students, mostly non-traditional, the Mean age is 32 with a standard deviation 12 students, and with a normal distribution. Six of these students are international students.

What is the probability that, if one student is picked at a random, he/she be a teenagers? You need to (somewhat) critically think about this before tackling it!!

What is the probability that if ONE student is selected at random, he/she will be an international student?

What is the probability that if on student is selected at random, his/her age be between 28 to 30 years old?

What is the probability that if on student is selected at random, his/her age be between 28 to 36 years old?

Suppose we select, at random, a sample of 9 students from this class. What is the probability that the mean age of that sample will be more than 38 years old?

Explanation / Answer

P(international studnet)=6/120

P(28<x<30)=P(28-32/12<z<30-32/12)=P(-0.33<z<-0.167)=0.1967

P(28<x<36)=P(-0.33<z<0.33)=0.2586

P(xbar>38)=P(z>38-32/(12/sqrt(9))=P(z>1.5)=0.0668

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.