f ( x ) = (0.4) 24 (0.6) x 24 , for x = 24, 25, .... E(X) ? Give your answer to
ID: 3073294 • Letter: F
Question
f(x) =
(0.4)24(0.6)x24, for x = 24, 25, ....
E(X)
? Give your answer to three decimal places.
d) What is
Var(X)
? Give your answer to three decimal places.
+ Question Dat is ! evbais Artswers Suppose that we have an unfair coin that its hcad occur with probability 0.4. LctX bethe number of trials nooded to get 24 heads, so that X ~ Neg,Din.(r-24, p-0.4), with pmf fx) u.4)24(0.6y24, forx-24, 25, 23 Consider a random sample of 25 ohservations X1 X225,each representing the numher of trials to obtain 24 heads of the unfair coin. a) What is E(X)2 Give your answer to three decimal places. h) What is Var(X)Gve your answer tn three derimal plares. c) What is E(X) ? Give your answer to three decimal places d) What is Var(X) ? Give your answer to three decimal places.Explanation / Answer
a)
E(X) = r/p = 24/0.4 = 60
b)
Var(X) = r* (1-p)/p^2
= 24 * 0.6 /.4^2
= 90
c)
E(Xbar) = E(X) = 60
d)
Var(Xbar) = Var(X) /n = 90 / 25
= 3.6
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.