Suppose 250 randomly selected people are surveyed to determine if they own a tablet. Of the 250 surveyed, 98 reported owning a tablet. Using a 95% confidence level, compute an upper bound estimate for the true proportion of people who own tablets. Round to three decimal places.

Let z_0.05 = 1.645, z0.1 = 1.28, z_0.025 = 1.96.

You flip an unfair coin until it shows a head. Given P(a head comes up) = 0.2.

What is the expected number of times of flipping?

Each multiple-choice question on an exam has

four choices. Suppose that there are 50 questions and the choice is selected

randomly and independently for each question. Let X denote the number of questions

answered correctly. 

Find E(X) and V(X).

Consider a sequence of independent Bernoulli trials

with p = 0.2. After the sixth success occurs, what is the expected number of

trials to obtain the seventh success?