Does soil filled with nitrogen increase the weight of worms when compared to soil without nitrogen? The weights of 14 randomly selected worms are taken, 7 in soil with nitrogen, and 7 in soil without nitrogen. The mean weights of worms in soil with nitrogen was 42.4 micrograms, while the mean weights of worms in soil without nitrogen was 39.4 micrograms. A researcher randomized the data over 100 trials, and the difference of means for each trial is shown in the dot plot below. What can the researcher conclude from this study?

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.