The standard deviation of a population is 13.
What is the margin of error?

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.

In one month jillian made 36 local phone calls and 20 long-distance calls what was her ratio of local calls to long-distance calls for that month?

The function below is written in vertex form or intercept form. rewrite them in standard form and show your work. y = -3(x-2)(x-4)