Question

6 На ферме 120 коров породы А и 180 коров породы В. Для проверки жир- ности молока фермер выбрал 50 коров. Сколько представителей каждой породы должен выбрать фермер, чтобы получить наиболее правильный результат? III​

Answer 1

Ответ:

20 коров с породы А

30 коров с породы В

Answer 2

Calculating the Number of Cows to Select for Milk Fat Testing

To determine the number of cows to select for milk fat testing from each breed, we can use a proportional sampling method based on the proportion of each breed in the total population of 300 cows.

Step 1: Calculate the Proportion of Each Breed We have 120 cows of breed A and 180 cows of breed B, making a total of 300 cows.

- Proportion of breed A = (Number of cows of breed A) / (Total number of cows) = 120 / 300 = 0.4 - Proportion of breed B = (Number of cows of breed B) / (Total number of cows) = 180 / 300 = 0.6

Step 2: Determine the Number of Cows to Select To obtain the most accurate result, the number of cows selected from each breed should be proportional to their representation in the total population.

- Number of cows to select from breed A = Proportion of breed A * Total number of cows to be selected - Number of cows to select from breed B = Proportion of breed B * Total number of cows to be selected

Step 3: Calculate the Results Substitute the values into the formulas to find the number of cows to select from each breed.

- Number of cows to select from breed A = 0.4 * 50 = 20 - Number of cows to select from breed B = 0.6 * 50 = 30

Therefore, the farmer should select 20 cows of breed A and 30 cows of breed B to obtain the most accurate result for testing the milk fat content.

This approach ensures that the sample for testing is representative of the entire population of cows on the farm