| 1 |
a
|
b
|
c
|
d
|
e
|
|
(i)
|
10 |
$7.50
|
6.2
|
62
|
480
|
|
(ii)
|
6
|
$6.04
|
4.4
|
45
|
82
|
|
(iii)
|
20
|
$10.60
|
8.6
|
85
|
628
|
|
(iv)
|
14
|
$4.56
|
4.2
|
40
|
546
|
|
(v)
|
24
|
$10.01
|
6
|
74
|
625
|
|
(vi)
|
13
|
$7.77
|
6.3
|
61.46
|
423
|
|
(vii)
|
8.26
|
$3.29
|
2.1
|
21.18
|
239.9
|
2. The 20th percentile is 7
The 70th percentile is between 41 and 46.
3.
|
x
|
x −
 |
(x −
)2 |
|
4
|
4 − 8 = -4
|
16
|
|
6
|
6 − 8 = -2
|
4
|
|
7
|
7 − 8 = -1
|
1
|
|
9
|
9 − 8 = 1
|
1
|
|
10
|
10 − 8 = 2
|
4
|
|
12
|
12 − 8 = 4
|
16
|
|
Total Σ(x −
)2 = |
42
|
= 8
Standard deviation = 2.65 (to 3 sig.fig.)
4.
|
x
|
f
|
f.x
|
x −
|
(x −
)2 |
f(x −
)2 |
|
4
|
1
|
4
|
-2
|
4
|
4
|
|
5
|
4
|
20
|
-1
|
1
|
4
|
|
6
|
9
|
54
|
0
|
0
|
0
|
|
7
|
6
|
42
|
1
|
1
|
6
|
|
8
|
0
|
0
|
2
|
4
|
0
|
|
Σ
|
20
|
120
|
14
|
= 6
Standard deviation = 0.84
