Hello! If you are in 5th grade or under and need help with homework I will be happy to help in any subject :)

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state 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.

Simplify (4x^2 - 8xy + 2y^2) - (9x^2 - 4xy - 7y^2) a. -5x^2 + 4xy + 9y^2 b. -5x^2 - 4xy + 9y^2 c. -5x^2 + 12xy + 4y^2 d. -5x^2 - 4xy - 5y^2