THE UNIVERSITY OF HONG KONG
08/09
DEPARTMENT OF STATISTICS AND ACTUARIAL SCIENCE
STAT0302 Business Statistics
Assignment 1
(Do all. Hand in solutions to the ﬁve starred questions on or before 4.2.09.)
1. (a) Give two examples of graphical presentation of data.
(b) Give two examples of tabular presentation of data.
(c) The lengths (in cm) of the 12 items of a batch are as follows: 38.5, 31.9, 32.5,
32.0, 31.8, 32.7, 32.0, 31.9, 32.0, 32.3, 30.4, 36.0. Find the mean, median, mode,
range, standard deviation, and skewness of the 12 data.
*2. The following are the numbers of minutes that a clinic kept its 80 patients waiting
beyond their appointment time on a certain day:
7.5
11.3
6.8
13.7
15.4
16.8
4.0
3.8
8.4
3.7
11.2
8.9
10.5
5.6
4.2
1.5
6.8
10.4
17.5
4.2
8.3
1.3
5.9
11.3
6.3
7.2
9.3
9.9
7.2
2.7
1.2
14.6
10.3
8.5
10.0
12.8
6.9
13.5
10.8
5.1
12.7
11.9
2.6
12.9
13.8
3.9
7.5
16.1
11.1
8.3
9.6
6.4
15.7
5.8
7.9
8.8
2.4
5.2
8.4
16.7
10.2
3.8
11.7
8.9
15.3
8.0
4.3
11.4
16.6
9.0
12.5
10.6
5.9
14.3
8.8
9.6
7.0
12.3
8.5
5.8
(a) Group these data into a frequency distribution table with classes 0
.
05

3
.
05,
3
.
05

6
.
05,
···
, 15
.
05

18
.
05.
(b) Treating the data as forming a population, ﬁnd the mean, median, mode, stan
dard deviation, coeﬃcient of variation and skewness from the
table
.
*3. The 120 employees of a company are divided into six grades. The numbers of
employees and their monthly salaries (in $1000) are given in the table below: