You want to know what proportion of adults in the United States use an electric toothbrush.  How many adults have to be surveyed to estimate this proportion with a margin of error of 3% using a 95% confidence interval?

A national polling organization does a survey of  995 people to estimate the percentage of all American adults who favor a ban on the use of cell phones while driving.  In the survey, 37% said they favor such a ban.   a.)  Find a 90% confidence interval for the proportion of all American adults who favor such a ban.  Also find the margin of error.  Round your answers to four decimal places.                      90% Confidence Interval:  (  [LL]  ,  [UL]  )                    Margin of Error:   [E]   b.)  Still using a 90% confidence interval, how many should be polled to reduce the margin of error to 2%?  Use the fact that in the first poll 37% said that they favor such a ban.                  Required sample size =  [n]

An Olympic archer is able to hit the bull’s eye 75% of the time.  Suppose she shoots 25 arrows.  For a – c, express your answer as a decimal rounded to four decimal places.    a.)  What is the probability she gets exactly 19 bull’s eyes?  [a] b.)  What is the probability that she gets at most 16 bull’s eyes?  [b]   c.)   What is the probability that she gets at least 14 bull’s eyes?  [c] d.)  If she shot 25 arrows many times, what is the mean and standard deviation of how many bull’s eyes she would get?  Round to one decimal place, if appropriate.              Mean = [mean]             Standard Deviation = [sd]

Suppose in the mass-spring system, the position function is given by

Find the general solution:

Suppose we are solving in equation in the form: In each of the following parts, determine the roots of the characteristic equation given a corresponding general solution:

Suppose in a mass spring system the ODE is where

Suppose we have a mass-spring system with an external force represented by an ODE in the form

The roots of the characteristic equation for y” +2y’+y=0 are:

After receiving change-of-shift report on four patients, which patient would the nurse assess first?