An advertising agency that serves a major radio station wants to estimate the mean amount of time the station’s audience members listen to the radio on a daily basis. From past studies the population standard deviation is known to equal 45 minutes. What sample size is needed if the agency wants to be 90% confident of being within (±) 5 minutes of the true mean amount of time audience members listen to the radio per day?

So the answer for this case would be n=220 rounded up to the nearest integer

Step-by-step explanation:

Information given

represent the population deviation

represent the margin of error

The margin of error for the true mean is given by this formula:

   (a)

And on this case we have that ME =5 and we are interested in order to find the value of n, if we solve n from equation (4) we got:

  (b)

The critical value for 90% of confidence interval now can be founded using the normal distribution. The significance level is and the critical value would be , replacing into formula (b) we got:

So the answer for this case would be n=220 rounded up to the nearest integer

answer: the dogs need to shift their focus to human scent.

its because the dogs being trained are for search and rescue thus they need to be able to track humans and their specific scent

is there any photos or whatever?