1.
|
Number of cars (x)
|
Tally
|
frequency (f)
|
f . x
|
|
1
|
|
16
|
16
|
|
2
|
|
9
|
18
|
|
3
|
|
7
|
21
|
|
4
|
|
5
|
20
|
|
5
|
11
|
2
|
10
|
|
6
|
1
|
1
|
6
|
|
Totals
|
40
|
91
|
a. Mean number of cars = 91 ÷ 40 = 2.275
b.
2.
|
Number of students
|
Frequency (f)
|
Midpoint |
f . x
|
|
1 − 20
|
87
|
10.5
|
913.5 |
|
21 − 40
|
324
|
30.5
|
9882
|
|
41 − 60
|
158
|
50.5
|
7979
|
|
61 − 80
|
23
|
70.5
|
1621.5
|
|
81 -100
|
8
|
90.5
|
724
|
|
Totals
|
600
|
21120
|
a. 
b. Mean = 35.2
Modal class is 21 − 40
3. a.
|
Height (cm)
|
Frequency (f)
|
Midpoint (x)
|
f.x
|
|
160 − 170
|
2
|
165
|
330
|
|
170 − 180
|
3
|
175
|
525
|
|
180 − 190
|
4
|
185
|
740
|
|
190 − 200
|
7
|
195
|
1365
|
|
200 − 210
|
4
|
205
|
820
|
|
20
|
3780
|
b.
c. The mean is 189
d. The modal class is 190 − 200
e.
|
Height (cm)
|
Cumulative Frequency |
|
160
|
0
|
|
170
|
2
|
|
180
|
5
|
|
190
|
9
|
|
200
|
16
|
|
210
|
20
|
f.(i) median = 192 cm
(ii) upper quartile = 198 cm
(iii) lower quartile = 180 cm
(iv) 80th percentile = 200 cm
(v) 10th percentile = 170 cm
