DESCRIBING DATA

DATA PRESENTATION

GRAPHIC PRESENTATIONOF QUALITATIVE DATA

• Bar chart: a graph that shows qualitative classes on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are proportional to the heights of the bars.

• Pie chart: a chart that shows the proportion or percentage that each class represents of the total number of frequencies.

MINUMAN FAVORIT RESPONDENBeverage Number

Cola-Plus 40

Coca-Cola 25

Pepsi 20

Lemon-Lime 15

Cola-Plus Coca-Cola Pepsi Lemon-Lime05

1015202530354045

TINGKAT PENDIDIKAN TERAKHIRPEKERJA DI PT “SUMBER MAKMUR”

PENDIDIKAN TERAKHIR

BANYAKNYA PEKERJA

SD 35

SMP 80

SMU/SMK 153

D3 40

S1 15

S2 5

SD; 35

SMP; 80

SMU/SMK; 153

D3; 40

S1; 15

S2; 5

PRESENTATION OF QUANTITATIVE DATA

• Frequency distribution table• Histogram• Frequency polygon• Cumulative frequency distribution• Cumulative frequency polygon

FREQUENCY DISTRIBUTION

• a grouping of data into mutually exclusive classes showing the number of observations in each class.

Hasil sampling mengenaiusia pengguna internet

50 7 30 42 32 47

36 27 15 41 16 26

37 30 31 53 11 29

36 20 31 43 30 19

45 26 22 41 30 48

Contoh 1:Usia Pengguna Internet (hasil sampling)

No. Usia (tahun) Frekuensi

1 5 hingga15 2

2 15 hingga25 5

3 25 hingga 35 11

4 35 hingga 45 7

5 45 hingga 55 5

(alternatif)

No. Usia (tahun) Frekuensi

1 5 -14 2

2 15 - 24 5

3 25 - 34 11

4 35 - 44 7

5 45 - 54 5

CONSTRUCTING FREQUENCY DISTRIBUTION

• Decide on the number of classes.• Determine the class interval/class width.• Set the individual class limits.• Tally the data into the classes.• Count the numberof items in each class.

Menentukan banyak kelas

• Banyaknya data = n = 30• Carilah bilangan asli k sekecil-kecilnya

sedemikian hingga 2k > 30• Jawab: k = 5

Menentukan lebar kelas

• H= 53• L = 7• i ≥ 9,2• i = 10

Menetapkan batas-batas kelas• Total jangkauan = 5.10 = 50• Jangkauan aktual = 46• Kelonggaran = 50 – 46 = 4• Kelonggaran/2 =4/2 = 2• Batas bawah kelas pertama = 7 – 2 = 5

No. Usia (tahun)

1 5 hingga15

2 15 hingga25

3 25 hingga 35

4 35 hingga 45

5 45 hingga 55

Distribusi Frekuensi Relatif

NO. USIA (TAHUN) FREKUENSI FREK. RELATIF1 5 - 14 2

0,072 15 - 24 5 0,173 25 - 34 11 0,374 35 - 44 7 0,235 45 - 54 5 0,17

JUMLAH 30 1,00

HISTOGRAM

• a graph in which the classes are marked on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are represented by the heights of the bars, and the bars are drawn adjacent to each other.