STAT20029 T2,2020 Week 2 Questions

STAT20029 (T2,2020) Questions:

Week 2

Activity 1

Calculate appropriate class width for the following Per capita GDP data and form the frequency distribution:

Review Problem 2.8

RP2.8: A company manufactures a metal ring, which usually weighs about 1.4 kg, for industrial engines. A random sample of 50 of these metal rings produced the following weights (in kg). Construct a frequency distribution for these data using FIVE classes. What can you observe about the data from the frequency distribution?

1.51

1.59

1.42

1.25

1.34

1.51

1.51

1.19

1.62

1.31

1.56

1.16

1.25

1.48

1.59

1.42

1.62

1.25

1.31

1.16

1.48

1.96

1.51

1.62

1.45

1.53

1.79

1.19

1.34

1.34

1.48

1.51

1.31

1.02

1.65

1.45

1.08

1.39

1.42

1.76

1.11

1.25

1.56

1.22

1.48

1.22

1.19

1.62

1.39

1.45

Practice Problem 2.4

PP2.4: The human resources manager for a large company commissions a study in which the employment records of 500 company employees are examined for absenteeism (days off work) during the past year. The consultant conducting the study organises the data into a frequency distribution, shown below, to assist the human resources manager in analysing the data. For each class of the frequency distribution, determine the class midpoint, relative frequency and cumulative frequency.

Class interval

Frequency

(0, 2]

218

(2, 4]

207

(4, 6]

56

(6, 8]

11

(8, 10]

8

Practice Problem 2.9

PP2-9: Construct a stem and leaf plot using two digits for the stem.

Practice Problem 2.14

PP2.14: The following data are monthly downloads (megabytes) on a handheld device. Construct a stem and leaf plot of the data, using whole part for the stem and the decimal part for the leaf. What does this plot tell you about monthly downloads on handheld devices?

Activity 2:

A sample of 29 factory workers were asked as to how long does it take each to travel from home to work on average. The following table provides their answers in minutes.

50 30 73 79 5 9

42 10 15 35 51 68

69 32 46 54 65 44

23 36 77 61 59 56

48 58 21 11 46

 Construct a stem-and-leaf plot of the data.

Activity 3:

A sample of 29 factory workers were asked as to how long does it take each to travel from home to work on average. The following table provides their answers in minutes.

50 30 73 79 5 9

42 10 15 35 51 68

69 32 46 54 65 44

23 36 77 61 59 56

48 58 21 11 46

Produce a frequency distribution table of the data using “0 to less than 10” as the first class.

Activity 4:

A sample of 29 factory workers were asked as to how long does it take each to travel from home to work on average. The following table provides their answers in minutes.

50 30 73 79 5 9

42 10 15 35 51 68

69 32 46 54 65 44

23 36 77 61 59 56

48 58 21 11 46

Draw a histogram using “0 to less than 10” as the first class.

Review Problem 2.9

RP2.9: In a medium-sized New Zealand city, 90 houses are for sale, each having about 180 m2 of floor space. The asking prices vary. The frequency distribution shown contains the price categories for the 90 houses. Construct a frequency polygon, ogive from these data.

Practice Problem 2.16

PP2.16: Is the total sales revenue related to the advertising dollars spent by a company? The following data represent the advertising dollars and the sales revenues for various companies in a given industry during a recent year. Construct a scatter plot of the data from the two variables and discuss the relationship between the two variables.

Advertising

($ million) Sales

($ million)

4.2 155.7

1.6 87.3

6.3 135.6

2.7 99

10.4 168.2

7.1 136.9

5.5 101.4

8.3 158.2

Practice Problem 2.11

PP2.11: The table below shows Department of Foreign Affairs and Trade data for the value (in A$ million) for the top 10 import sources. Produce a bar chart for these data. On the basis of the charts for this and the previous problem, comment on Australia’s major business partners.

Import market

A$ million

China

49329

USA

39181

Japan

21221

Singapore

17878

Thailand

13832

Germany

13099

UK

12044

Malaysia

10944

South Korea

10813

New Zealand

10532

Practice Problem 2.10

PP2.11: The table below shows Department of Foreign Affairs and Trade data for the value (in A$ million) of Australian exports to the top 10 buyers of Australian goods. Construct a pie chart to represent these data. Label the slices with the corresponding percentages and give the chart an appropriate title. Comment on the effectiveness of using a pie chart to display these data.

Export market

A$ million

China

94655

Japan

47501

South Korea

19610

USA

9580

India

9517

New Zealand

7399

Singapore

5659

Taiwan

7356

UK

3859

Malaysia

5561

Activity 6:

In order to improve the customer satisfaction rating, the owner of a restaurant reviews the customer feedback forms received in past one year and summarises the type of complaints and the number of complaints received as given below:

Cost

Percentage (%)

Long waiting time

9

Food too salty

6

Overpriced

26

Small portions

21

Food not fresh

16

No atmosphere

12

Unfriendly staff

7

Other

3