C10 Write a nation named fifth with a single vector argument x that calculates and returns 5th 10th, 15th, ... elements of x. You may assume that x has ar 8.10 where x is the sample mean. Write an R function named fifth with a singl the sample mean of the 5th, 10th, 15th, ... elements of least five elements. o rdinate system uses X, the signed horizontal distance from the ntal distance from the origin distance from e from the origin, to describe the point (x, y). The polar -ac r, the signed distance from the orizin, and the har axis, to descr