Question

Statistics Question?

Answer 1

In order to ensure the safety of school classrooms, the localfire marshall does an inspection at Thomas Jefferson High School every month, looking for faulty wiring, overloaded circuits, etc. At TJHS, the new academic wing has 5 math rooms, 10 science rooms, and 10 English rooms. The science rooms are divided into 8 biology and 2 chemistry rooms. Each month, the fire marshallrandomly picks one of the rooms in the new wing to inspect. Define the following events:

S = the event the selected room is a science room
B = the event the selected room is a biology room
M = the event the selected room is a math room
E = the event the selected room is an English room
C= the event the selected room is a chemistry room

Calculate the probabilities of the events described below:

a) P(S)
b) P(M or E )
c) P(E or B)
d) P(S and not C)

Answer 2

@Abhisar @abb0t @pooja195

Answer 3

@SolomonZelman

Answer 4

hey i was about to tag that

Answer 5

LOL!!!

Answer 6

:P

Answer 7

@TheSmartOne

Answer 8

well, the picked room is 1, out of (5 math rooms + 10 science rooms + and 10 English rooms

10 science= 8 biology rooms + 2 chemistry rooms.

these are the condition

Answer 9

s

Answer 10

So, 25 rooms altogether

abbreviations
```
S = the event the selected room is a science room
B = the event the selected room is a biology room
M = the event the selected room is a math room
E = the event the selected room is an English room
C= the event the selected room is a chemistry room
```

YOU NEED

a) P(S)
b) P(M or E )
c) P(E or B)
d) P(S and not C)

Answer 11

lets start from a.
if there are 10 science classrooms, and 25 classrooms altogther,
THEN what is P(S) ?

Answer 12

I think the answer to A. is 10/25 but I'm not 100% sure.

Answer 13

yes

Answer 14

now, reduce this fraction

Answer 15

I have to reduce it to 2/5 right? I wasn't sure if I needed to do that part.

Answer 16

yes

Answer 17

Now, for b.
you have P(M or E )
so any result either M or E is satisfactory for you.

there are 10 English clasrooms, and 5 math classrooms.

Answer 18

how many math and English clasroms are there togther?

Answer 19

I was thinking that B was 15/25 which would be 3/5 right?

Answer 20

oh, very nice !!!

Answer 21

Now, c.

P(E or B)

how mnay biology and english classroms are there togther ?

Answer 22

18/25 Which can not be reduced right?

Answer 23

yup !

Answer 24

So that's my answer for C right?

Answer 25

now, part d.

P(S and not C)

Answer 26

How many science classroms are there that are not chemistry classrooms ?

Answer 27

8 (the 8 biology classrooms)

Answer 28

yes

Answer 29

So,
probabilty of science room, but not chemistry means, that we are looking fro a probability that a biology room will be that room

Answer 30

so what is part d?

Answer 31

D is 8/25 Which is already reduced right?

Answer 32

yup

Answer 33

if you think about it, it isn't hard- as you have just proven:)

Answer 34

So the correct answers are.

P(S) = 2/5
P(M or E ) = 3/5
P(E or B) = 18/25
P(S and not C) = 8/25

Answer 35

@SolomonZelman Is there any work I can show on how we got the answer? Or is it as easy as saying, like for example A - 10/25 is science and then reduced to 2/5 as my answer. etc..

Answer 36

well, you can certainly explain your answers.

Answer 37

like jst imagine you are the teacher for a second, and explain it.
(as long as you get it, and I see that you do)

Answer 38

Oh Ok.. Thanks so much @SolomonZelman

Answer 39

You did most of the work, and I only directed you. And apparently, you know the direction from now and - which is the most important thing..... You are surely welcome!