# Thread: Probability Help Questions!!!!!!! URGENT!

1. ## Probability Help Questions!!!!!!! URGENT!

Heya,

Could you please explain to me how you would do these. You might need a calculator.

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The probability that Travis scores a goal in basketball fromthe 3 metres line is 0.65. In the last 4 mintues of practice, he shoots for a basket 8 times.

The chance he scores 5 goals is:

The probability he scores atleast 2 goals is:

The probability that he scores goals only with the first 6 shots are:

2. Originally Posted by mibamars
Heya,

Could you please explain to me how you would do these. You might need a calculator.

__________________________________________________ ___________

The probability that Travis scores a goal in basketball fromthe 3 metres line is 0.65. In the last 4 mintues of practice, he shoots for a basket 8 times.

The chance he scores 5 goals is:

The probability he scores atleast 2 goals is:
these two questions are just using the binomial distribution. (do you remember the formula?)

we have $P(\mbox{k goals in 8 tries}) = P(X = k) = {8 \choose k}(0.65)^k(0.35)^{8 - k}$

for the first question, you want $P(5)$

for the second, you want $P(X \ge 2) = P(2) + P(3) + \dots P(8) = 1 - P(0) - P(1)$

The probability that he scores goals only with the first 6 shots are:
this means he scores the first 6 times and then misses the last two times.

the probability is: $(0.65)^6(0.35)^2$

3. I dont think you are right.

1) 0.279

2) 0.996

3) 0.009

I would just like to know how they got them.

4. Originally Posted by mibamars
I dont think you are right.

1) 0.279

2) 0.996

3) 0.009

I would just like to know how they got them.
ok, apparently you're confused about something, because those are exactly the answers my solutions give.

what are you not sure about? do you know what ${8 \choose k}$ means, for instance? i mean $_8C_k$, as in the combination