Suppose you have a binary randomized controlled experiment designed to measure the causal effect of X on Y. Let the control group be identified by X​ = 0 and the treatment group by X​ = 1. The differencesofmeans ​estimator, denoted by ​, is an estimator of the causal effect of X on Y because the differencesofmeans estimator​ estimates: A. the change in the expectation of Y as result of an observation being in the treatment group as opposed to the control group. B. the expectation of Y for observations within the control group. C. the expectation of Y for observations within the treatment group. D. All of the above.

I've been working on this for a few days and i just don't understand, it's due in a few hours. you.the direction of a vector is defined as the angle of the vector in relation to a horizontal line. as a standard, this angle is measured counterclockwise from the positive x-axis. the direction or angle of v in the diagram is α.part a: how can you use trigonometric ratios to calculate the direction α of a general vector v = < x, y> similar to the diagram? part bsuppose that vector v lies in quadrant ii, quadrant iii, or quadrant iv. how can you use trigonometric ratios to calculate the direction (i.e., angle) of the vector in each of these quadrants with respect to the positive x-axis? the angle between the vector and the positive x-axis will be greater than 90 degrees in each case.part cnow try a numerical problem. what is the direction of the vector w = < -1, 6 > ?