class mark A. Show that if all class intervals have equal size c, then (a) the deviations are all multiples of c (i.e., dj = cuj , where uj = 0; -1, -2; XXXXXXXXXXand (b) the arithmetic mean can be...

class mark A. Show that if all class intervals have equal size c, then (a) the deviations are all multiples of c (i.e., dj = cuj , where uj = 0; -1, -2; . . .) and (b) the arithmetic mean can be computed from the formula

2. Use the result of Problem 3.21(b) to find the mean height of the 100 male students at XYZ University (see Problem 3.20).

3. Compute the mean weekly wage of the 65 employees at the P&R Company from the frequency distribution in Table 2.5, using (a) the long method and (b) the coding method.