Areport in a research journal states that the average weight loss of people on a certain drug is 27 lbs with a standard deviation of 5 lbs. if this study is repeated, how large should the sample size be so that the margin of error would be no more than 2.5 lbs with 95% confidence?

Find the number of positive three-digit even integers whose digits are among 9, 8, 7,5, 3, and 1.

What does x = in this equation x+3+2x=x+5

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.