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MATHEMATICS TEACHER 9 GRADE

MR. DEDI

Learning Instructions

(Langkah-langkah umum cara belajar secara mandiri atau bersama disekolah yang harus dipahami oleh siswa)

• Awali kegiatan belajar dengan berdoa.

• Silakan mempelajari Learning Materials terlebih dahulu untuk mendapat pemahaman yang baik terkait topik/ materi yang akan dipelajari.

• Setelah mendapat pengalaman belajar dan memahami topik/materi dengan baik silakan lanjutkan ketahap Exercises. Apabila belum siap silakan mempelajari kembali Learning Materials atau bertanya kepada guru melalui WA / memanfaatkan link Ask To Chat GPT yang tersedia. 

Note : Jangan belajar sekedarnya, ikutilah  petujuk belajar di atas untuk mendapat hasil yang lebih maksimal.

STATISTICS

The Average, Median, Mode, and Number of Data
for Junior High School Class IX

A. Definition of Statistics

Statistics is a science that studies how to collect, process, present, and analyze data. In basic statistics, there are several important measures, namely the amount of data, the average, the median, and the mode.

B. Jumlah Data (S)

1. Definition
   The amount of data is the result of the sum of all data values.

2. Rumus
   Σx = x₁ + x₂ + x₃ + ... + xn

3. ExampleData: 5, 6, 7, 8, 9
   Total data:
   Σx = 5 + 6 + 7 + 8 + 9 = 35

C. Average (Mean)

1. DefinitionAverage is the value obtained from the sum of all data divided by the amount of data.

2. RumusRata-rata = Σx / n

Description:
Σx = number of data = lot of data

3. ExampleData: 6, 7, 8, 9
   Σx = 30
   n = 4Average = 30 ÷ 4 = 7.5

4. Diagram Batang

Value9 | █8 | █ █7 | █ █6 | █ █ █

 6  7  8  9 

The average line is at a value of 7.5

D. Median

1. The median definition is the middle value of the data that has been sorted.

2. Median on Odd Data

Example data: 3, 5, 7, 9, 11Median = 7

Number line diagram:3 — 5 — 7 — 9 — 11
  ↑
  Median

3. Median on Even Data

Example data: 4, 6, 8, 10Median = (6 + 8) ÷ 2 = 7

Number line diagram:4 — 6 — 8 — 10
  ↑ ↑ central
  data

E. Mode

1. DefinitionMode is the value that appears most often in a data.

2. ExampleData: 5, 6, 6, 7, 8Mode = 6

3. Diagram Batang

Frequency3 | █2 | █ █1 | █ █ █ █

 5  6  7  8 

The highest bar indicates a mode of 6.

F. Sample Complete Questions

Retest value data:6, 7, 8, 6, 9, 7, 6

Number of data = 49Lot of data = 7Average = 49 ÷ 7 = 7Median = 7Mode = 6

G. Conclusion

1. The amount of data is the sum of the entire value of the data.

2. The average indicates the overall value of the data.

3. The median is the middle value of the data.

4. Mode is the most frequently occurring value.

STATISTIKA
Rata-rata, Median, Modus, dan Jumlah Data
Kelas IX SMP

A. Pengertian Statistika

Statistika adalah ilmu yang mempelajari cara mengumpulkan, mengolah, menyajikan, dan menganalisis data. Dalam statistika dasar terdapat beberapa ukuran penting, yaitu jumlah data, rata-rata, median, dan modus.

B. Jumlah Data (Σ)

4. Pengertian
   Jumlah data adalah hasil penjumlahan seluruh nilai data.

5. Rumus
   Σx = x₁ + x₂ + x₃ + ... + xₙ

6. Contoh
   Data: 5, 6, 7, 8, 9
   Jumlah data:
   Σx = 5 + 6 + 7 + 8 + 9 = 35

C. Rata-rata (Mean)

3. Pengertian
   Rata-rata adalah nilai yang diperoleh dari jumlah seluruh data dibagi dengan banyaknya data.

4. Rumus
   Rata-rata = Σx / n

Keterangan:
Σx = jumlah data
n = banyak data

5. Contoh
   Data: 6, 7, 8, 9
   Σx = 30
   n = 4
   Rata-rata = 30 ÷ 4 = 7,5

6. Diagram Batang

Nilai
9 | █
8 | █ █
7 | █ █
6 | █ █ █

 6  7  8  9 

Garis rata-rata berada di nilai 7,5

D. Median

3. Pengertian
   Median adalah nilai tengah dari data yang telah diurutkan.

4. Median pada Data Ganjil

Contoh data: 3, 5, 7, 9, 11
Median = 7

Diagram garis bilangan:
3 — 5 — 7 — 9 — 11
     ↑
   Median

4. Median pada Data Genap

Contoh data: 4, 6, 8, 10
Median = (6 + 8) ÷ 2 = 7

Diagram garis bilangan:
4 — 6 — 8 — 10
  ↑  ↑
 data tengah

E. Modus

4. Pengertian
   Modus adalah nilai yang paling sering muncul dalam suatu data.

5. Contoh
   Data: 5, 6, 6, 7, 8
   Modus = 6

6. Diagram Batang

Frekuensi
3 | █
2 | █ █
1 | █ █ █ █

 5  6  7  8 

Batang tertinggi menunjukkan modus yaitu 6.

F. Contoh Soal Lengkap

Data nilai ulangan:
6, 7, 8, 6, 9, 7, 6

Jumlah data = 49
Banyak data = 7
Rata-rata = 49 ÷ 7 = 7
Median = 7
Modus = 6

G. Kesimpulan

5. Jumlah data adalah total seluruh nilai data.

6. Rata-rata menunjukkan nilai keseluruhan data.

7. Median adalah nilai tengah data.

8. Modus adalah nilai yang paling sering muncul.

Video

Exercises

(Exercises merupakan latihan soal yang dikerjakan setelah belajar mandiri) 

PRACTICE EXERCISES: PIE CHART

Instructions:

1. Convert the following data into a pie chart.

2. Calculate the percentage (%) and the angle (in degrees) for each category.

3. Use a protractor to draw the pie chart neatly.

A. Simple Data Questions

Question 1

Students’ hobbies in Grade 9:

• Football = 12 students

• Reading = 8 students

• Playing games = 10 students

• Music = 10 students

Total students = 40

Draw a pie chart based on the data above.

Question 2

Types of transportation used by students to go to school:

• Bicycle = 15 students

• Motorcycle = 20 students

• Public transportation = 5 students

Total students = 40

Draw an appropriate pie chart.

B. Percentage Data Questions

Question 3

Results of a survey on students’ favorite drinks:

• Tea = 30% 

• Juice = 25% 

• Milk = 20% 

• Mineral water = 25% 

Draw a pie chart based on the data. 

Question 4

Students’ daily study time distribution: 

• Mathematics = 40% 

• Science = 25% 

• Language subjects = 20%

• Others = 15%

Draw a pie chart and calculate the angle for each part.