a physics instructor gives his students a 10 point quiz, but due to a mix up the quiz contains questions about history not physics. since none of the physics students have studied history, each of them selects answers by randomly guessing. there are 10 questions on the quiz each with 5 possible answers.
i dont understand how im suppose to figure this out if i dont know any percentages. and what probabilty model and i suppose to use the binomial one?
thats what i think your suppose to do but i dont know that percentage to type in.
a) compute the probability that a student gets all of the questions correct.
b) compute the probability that a student gets exactly 4 questions correct.
binompdf(10,_,4)
c)compute the probability that a student gets no more that 4 questions correct.
pinomcdf(10,_,4)
d) compute the probability that a student gets at lease 4 questions correct.
1-bonomcdf(10,_4)
e) on average how many questions do you expect a student will get correct?
10*_=
f) with what standard deviation?
sqr(10*_*_) =
so would it be 0.05 for the probabilty than?
i dont understand how im suppose to figure this out if i dont know any percentages. and what probabilty model and i suppose to use the binomial one?
thats what i think your suppose to do but i dont know that percentage to type in.
a) compute the probability that a student gets all of the questions correct.
b) compute the probability that a student gets exactly 4 questions correct.
binompdf(10,_,4)
c)compute the probability that a student gets no more that 4 questions correct.
pinomcdf(10,_,4)
d) compute the probability that a student gets at lease 4 questions correct.
1-bonomcdf(10,_4)
e) on average how many questions do you expect a student will get correct?
10*_=
f) with what standard deviation?
sqr(10*_*_) =
so would it be 0.05 for the probabilty than?
-
binomial distribution
p = 1/5 = 0.2
e. E[x] = np = 10*0.2 = 2
f. SD = sqrt(npq) = sqrt(10*0.2*0.8) = 1.2649
p = 1/5 = 0.2
e. E[x] = np = 10*0.2 = 2
f. SD = sqrt(npq) = sqrt(10*0.2*0.8) = 1.2649