Question

solve

Answer 1

I realized the question but i don't realize that what does this question want!!!Can you tell me?

Answer 2

i also dont know
thats y i post this question here

Answer 3

This is a difficult question !
I realized that what does the question want but i can't solve!

Answer 4

If X=# of scouts (out of the 2 in the sample) trained in first aid then, then what are the possible outcomes for X?

Answer 5

X=0, 1 or 2. Now you need the probability for each case, and keep in mind that the sum of the probabilities must =1.

To get you started, let's find P(2). That means that the 1st scout chosen is trained, and then the 2nd scout chosen is trained. These are dependent events, since once the first scout is chosen, that determines the probability for the outcome that the 2nd scout is trained. So when the first scout is chosen, P(trained)=30/50. For the 2nd scout, P(trained|1st was trained)=29/49. So we have:

\[P(2)=\frac{ 30 }{50 }\frac{ 29 }{ 49 }=\frac{ 3 }{5 }\frac{ 29 }{ 49 }=\frac{ 87 }{ 245 }\]

You could convert that to a decimal, but personally, I'd probably just leave as fractions for now.

Now, can you come up with P(0) and the P(1)? (Notice: there are two ways for X=1 to occur.)

Answer 6

As for the mean, the mean of the distribution will just be\[\mu=\sum(x)\cdot P(x)\]