Which two sentences about inferences based on numeric variables are true? A strong positive or negative correlation can be used to prove a causal relationship, while the absence of correlation can be used to rule out a causal relationship. The absence of correlation can be used to rule out a causal relationship, but the presence of a strong positive or negative correlation does not prove a causal relationship. Strong correlations between two variables are sometimes explained by the influence of a third lurking variable that has a causal relationship with both variables. If a variable is known to be affected by multiple causes, its strong positive or negative correlations with other variables are likely to be spurious.

Which best describes the idea behind the "invisible hand"? producers decide what to make for consumers, which guides the economy. individuals seeking their own self interest benefit the economy as a whole. government sets policy for producers and consumers, which guides the economy. consumers decide what they need and want to buy, which guides the economy.

The symbols found on the map below indicate where fossils have been found in the same layer of sediment. each unique symbol represents fossil locations of a particular species.

“dear sir: it is with great reluctance, i trouble you on a subject, which does not fall within your province; but it is a subject that occasions me more distress, than i have felt, since the commencement of the war; and which loudly demands the most zealous exertions of every person of weight and authority, who is interested in the success of our affairs. i mean the present dreadful situation of the army for want of provisions, and the miserable prospects before us, with respect to futurity. it is more alarming than you will probably conceive, for, to form a just idea, it were necessary to be on the spot. for some days past, there has been little less, than a famine in camp. a part of the army has been a week, without any kind of flesh, and the rest for three or four days. naked and starving as they are, we cannot enough admire the incomparable patience and fidelity of the soldiery, that they have not been ere this excited by their sufferings, to a general mutiny or dispersion. strong symptoms, however, discontent have appeared in particular instances; and nothing but the most acitive efforts every where can long avert so shocking a catastrophe.” what’s the central idea?