A copper smelting process is supposed to reduce the arsenic content of the copper to less than 1000 ppm. Let μ denote the mean arsenic content for copper treated by this process, and assume that the standard deviation of arsenic content is σ = 140 ppm. The sample mean arsenic content X¯¯¯ of 95 copper specimens will be computed, and the null hypothesis H0: μ ≥ 1030 will be tested against the alternate H1: μ < 1030. For what values of X¯¯¯ should H0 be rejected so that the power of the test will be 0.9 when the true mean content is 985? Round the answer to two decimal places.

The rejection region should be X¯¯¯ ≤

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 > ?