Hurry i need help plz

If a baby uses 15 diapers in 2 days how many diapers will the baby use in a year

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.

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?