Will fan and medal
15% of Mrs. Landry’s students live in Lafayette, Louisiana. Mrs. Landry plans on selecting 15 out of all her students to send postcards to. Find the probability that Mrs. Landry would select exactly 5 students who live in the Lafayette area to send postcards to out of the 15.

Question

Will fan and medal
15% of Mrs. Landry’s students live in Lafayette, Louisiana.  Mrs. Landry plans on selecting 15 out of all her students to send postcards to.  Find the probability that Mrs. Landry would select exactly 5 students who live in the Lafayette area to send postcards to out of the 15.

photon336 · Answer

Here is an attempted answer. 

the probability that a student selected out of her class lives in Louisiana is $$0.15$$

$$\frac{ number~of~desired~outcomes }{ total~possible~outcomes  } = \frac{ 5 }{ 15 }$$

i'm not exactly sure but i'm wondering if we can multiply the two events together. 

$$(\frac{ 5 }{ 15 })(\frac{ 15 }{ 100 }) = (\frac{ 3 }{ 60 })$$

photon336 · Answer

@Kainui

anonymous · Answer

thank you very much @Photon336 I just could not find the right formula throughout my whole unit. Much appreciated.

photon336 · Answer

Yeah when dealing with any probability problem it's the number of outcomes you're looking for over the total number of outcomes.