Lesson 9 cont..pptx. Statistics and probability

Mathematics 11

1. PRAYER

2. LET’S HAVE A RECAP

3. What is random sampling? What are the types of random sampling technique ? What are the types of non-probability sampling technique?

4. At the end of the lesson, the students should be able to: determine the sample size required for a given population using Slovin’s Formula; calculate the sample size for each category of given population; compute for the sample mean; apply this knowledge in solving real-life problem.

5. Supposing that your school has a population of 5,000 students and you want to know the average height of the students, it would be impractical to interview or to get the height of all students. All you need to do is to determine the sample size that will estimate the whole population. To do this, we will use the Slovin’s Formula in getting the sample size.

6. Hence, you must select randomly 371 students as your sample. The result is rounded up since this is getting samples from a population.

7. If the sample size obtained will be distributed by the table below, how many samples will be taken randomly from each Grade level.

8. Solution: To get the sample size from each Grade level, divide the number of students per year level by the total number of students then multiply the quotient by the required sample size

9. Grade 7: (1,100  5,000) x 371 = 81.62 ≈ 82 students Grade 8: (980  5,000) x 371 = 72.72 ≈ 73 students Grade 9; (900  5,000) x 371 = 66.78 ≈ 67 students Grade 10: (850  5,000) x 371 = 63.07 ≈ 63 students Grade 11: (680  5,000) x 371 = 50.46 ≈ 50 students Grade 12: (490  5,000) x 371 = 36.36 ≈ 36 students 371 students

10. Now that you know how to determine the sample size of a certain population, you are now ready to learn how to compute the sample mean which serves as an estimator for the population mean.

11. Example: The heights in meters of 5 students chosen at random are 1.5, 1.23,1.6, 1.4, and 1.3. The mean height of these 5 students is computed as, Mean= Mean= 1.41 meters  

12. Direction: Compute the mean of the following. The following shows the grades in Mathematics of the 15 randomly chosen students from Grade 11- STEM . 85, 89, 85, 81, 86, 89, 89, 92, 91, 95, 92, 86, 81, 87, 88 ACTIVITY: FINDING THE MEAN Mean= 87.73

13. Direction: Compute the mean of the following. 2. The following shows the monthly income of 12 randomly chosen families in a certain barangay . Php. 15,000 Php. 18,000 Php. 16,000 Php. 20,000 Php. 19,000 Php. 18,00 Php. 16,000 Php. 20,000 Php. 23,000 Php. 20,000 Php. 23,000 Php. 21,000 ACTIVITY: FINDING THE MEAN Mean= Php. 19,083.33

14. Direction: Compute the mean of the following. 3. The weights of 35 grade 10 class –A students are recorded as follows: ACTIVITY: FINDING THE MEAN Mean= Php. 40.29

15. Are there instances in your life wherein you compute for the average or mean? or getting a sample from a particular population?

16. What is the Slovin’s Formula? Do you understand now how to get the sample size for a particular population? Were you able to get the sample mean?

17. Direction: Determine the sample size required for the given population using the Slovin’s Formula and fill in the table below . An experimental study has a population of 10,000. At 5% margin of error, what would be its sample size ? ACTIVITY: DETERMINING SAMPLE SIZE

18. 2. Distribute the sample size obtained in number 1 as classified to the following categories. ACTIVITY: DETERMINING SAMPLE SIZE

19. Direction: Determine the sample size required for the given population using the Slovin’s Formula and fill in the table below . Find the sample size required using the Slovin’s Formula from a population of 20,000 given a margin of error of 5%. Distribute the sample size obtained in number 1 as classified to the following categories: ASSIGNMENT: