A researcher studying public opinion of propose d Social Security changes obtains a simple random sample of 50 adult Americans and asks them whether or not they support the propose d changes. To say that the distribution of pˆ p^, the sample proportion of adults who respond yes, is approximately normal, how many more adult Americans does the researcher need to sample if (a) 10% of all adult Americans support the changes?
(b) 20% of all adult Americans support the changes?

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)