Question

Only 30% of students consider statistics to be an exciting subject. Find the probability that I must ask more than 5 students before I get one who consider statistics to be an exciting subject.

.0720

.1681

.8319

.9280

Answer 1

$\text{let p(k) the probability that the student considers statistics}\newline \text{ to be an interesting subject.}$

$\text{where k is the number of respondents}$

$p(k>5)= 1-p(1)-p(2)-p(3)-p(4)-p(5)$

$p(k>5)= 1-0.3-0.3*0.7-0.3*0.7^2-$

$0.3*0.7^3-0.3*0.7^4 \approx0.1681$

Answer: 0.1681