A. An instructor gives a 100-point exam in which grades are normally distributed. The mean is 65 andthe standard deviation is 10. If there are 10% A's, 10% B's, 60% C's, 8% D's, and 12% F's, nd the scoresthat divide the distribution into those categories. B.) Using the mean and variance in the problem, what is the probability that the sample average of the final grades for 36 students is above 67?

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 > ?