In order to ensure efficient usage of a server, it is necessary to estimate the mean number
of concurrent users. according to records, the average number of concurrent users at 100
randomly selected times is 37.7, with a standard deviation ? = 9.2.
(a) construct a 90% confidence interval for the expectation of the number of concurrent
users.
(b) at the 1% significance level, do these data provide significant evidence that the mean
number of concurrent users is greater than 35?

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.

Me find the value of x each figure.

Acd that is originally priced at $15.85 red-tagged for the sale. what is the sale price of the cd