We have been given that a bag contains 4 red marbles, 7 blue marbles, and 6 green marbles. We are asked to find the probability of choosing a blue marble when one marble is drawn.
Therefore, the probability of choosing a blue marble is .
Let p be the true proportion of US adults who believe raising the minimum wage will help the economy. A point estimate for p is and a good aproximation (because we have a large sample) for the standard deviation of is . Therefore, a 99% confidence interval for p is given by where and is the th quantile of the standard normal distribution, so we have, , i.e., or equivalently (0.3798, 0.4602).