Aria is an assistant HR manager. She is helping the manager shortlist candidates by their required salary for the post of management trainee. The following are the required salary (in $) from 50 candidates:

3,000 2,500 3,250 2,950 2,900 4,000 3,100 2,700 2,850 2,600 3,700 3,250 2,750 2,480 2,300 3,640 3,680 3,360 3,250 2,950 2,800 2,780 3,110 2,670 3,450 2,650 3,750 3,150 2,780 3,580 4,000 3,600 3,650 4,200 3,560 2,700 2,900 3,250 2,650 3,200 2,500 3,150 2,630 2,145 2,770 3,250 2,580 2,580 3,850 3,350

a. Determine the appropriate number of classes for the required salary.

b. Use finding in part

a, and find the class width for the required salary.

c. Construct a cumulative relative frequency distribution for the required salary.

d. Construct an ogive for the required salary. If the manager plans to interview the bottom 70% of the interviewees based on the required salary, what is the maximum required salary she will consider for the interview?