Question

1) An Olympic archer is able to hit the bull’s-eye 80% of the time. Assume that each shot is independent of the others. If she shoots 6 arrows, what is the probability of each result below?
a) She gets exactly 4 bull’s-eyes.

Answer 1

correct

Answer 2

the question is what is the probability that she gets exactly 4

Answer 3

o

Answer 4

ya

Answer 5

well there i cant help you sorry

Answer 6

@jim_thompson5910 this person needs help and i cant help them but they have been trying for a long time can you help

Answer 7

Use the binomial probability distribution

(n C k)*(p)^(k)*(1-p)^(n-k)

where in this case

n C k = combination of n choose k
n = 6 (six arrows total are shot)
k = 4 (we want to know the probability of getting exactly 4)
p = 0.80 (decimal form of 80%)


For more info, check out

http://www.stat.yale.edu/Courses/1997-98/101/binom.htm

Answer 8

thanks jim

Answer 9

you're welcome

Answer 10

tell me what you get teenagerunaway

Answer 11

Thank you both of you!

Answer 12

i got .24

Answer 13

same here and you can use this handy calculator to check (but it helps to know how to do it through the formula)

http://stattrek.com/online-calculator/binomial.aspx

Answer 14

well more accurately 0.24576

Answer 15

how would i do a problem saying no more than

Answer 16

"no more than" means "less than or equal to"

Answer 17

so what you have to do is calculate the individual probabilities from k = 0 to k = max limit, then add them up

Answer 18

so it would be P(x less than equal to x?

Answer 19

more like P(x <= k) but you have the right idea

Answer 20

Thank you so much!

Answer 21

for instance, in that calculator I posted, it would be the line that says "Cumulative Probability: P(X ≤ 4)" (in this case, k = 4)

Answer 22

Got it