Question

Certain kinds of tumors tend to recur. The following data represent the lengths of time, in months, for a tumor to recur after chemotherapy (Reference: D.P. Byar, Journal of Urology, Vol. 10, pp. 556-561).

19	18	17	1	21	22	54
46	25	49	50	1	59	39
43	39	5	9	38	18	14
45	54	59	46	50	29	12
19	36	38	40	43	41	10
50	41	25	19	39	27	20

For this problem, use five classes.

(a) Find the class width.

(b) Make a frequency table showing class limits, class boundaries, midpoints, frequencies, relative frequencies, and cumulative frequencies. (Give relative frequencies to 2 decimal places.)

Class Limits

Class Boundaries

Midpoint

Frequency

Relative Frequency

Cumulative Frequency

(c) Draw a histogram.

(d) Draw a relative-frequency histogram.

Categorize the basic distribution shape.

bimodal

   uniform  

   skewed left

   mound-shaped symmetrical

   skewed right

(f) Draw an ogive. (Graph each point and the closed line segments connecting the points to create your graph.)

Answer 1

a) Here the maximum value = 59

minimum value = 1

No.of classes = 5

Class width = (59 - 1)/5 = 11.6

So, approximately class width is 12