Question

The hydrocarbon emissions at idling speed in parts per million (ppm) for automobiles of 1980 and 1990 model years are given for 20 randomly selected cars.

1980 models:

141	359	247	940	882	494	306	210	105	880
200	223	188	940	241	190	300	435	241	380

1990 models:

140	160	20	20	223	60	20	95	360	70
220	400	217	58	235	380	200	175	85	65

• (b) Construct a relative frequency histogram of the 1980 data on Excel and share screenshot
• (c) Construct a stem-and-leaf display of the 1990 data on Excel and share screenshot

Answer 1

Models
1980	1990
141	140
359	160
247	20
940	20
882	223
494	60
306	20
210	95
105	360
880	70
200	220
223	400
188	217
940	58
241	235
190	380
300	200
435	175
241	85
380	65

(b)

Class	Relative frequency	frequency
100-200	0.2	4
200-300	0.3	6
300-400	0.2	4
400-500	0.1	2
500-600	0	0
600-700	0	0
700-800	0	0
800-900	0.1	2
900-1000	0.1	2

Relative frequency histogram is:

(c)->

Steam and leaf of 1990 models is:

Steam	Leaf
0	20	20	20	58	60	65	70	85	95
1	40	60	75
2	0	17	20	23	35
3	60	80
4	0

Here, units of steam is hundred.