Question

На заводе 30% произведённых подшипников имеют дефект. при контроле качества продукции выявляется 65% дефектных подшипников. остальные подшипники поступают в продажу. найдите вероятность того, что случайно выбранный при покупке подшипник не имеет дефектов. если ответ округлите до сотых Помогите............ ​

Answer 1

Ответ:

Пошаговое объяснение:

Пусть X - количество произведенных подшипников.

Тогда 0,7X - количество подшипников, не имеющих дефект.

0,3X - количество подшипников с дефектом до контроля качества.

0,3*(1-0,65)X = 0,105X - количество дефектных подшипников, поступивших в продажу после контроля качества.

Тогда вероятность того, что случайно выбранный при покупке подшипник не имеет дефектов равна:

P = 0,7X/(0,105X+0,7X) = 0,7/0,805 = 0,8695...

Округляя до сотых, получаем 0,87.

Answer 2

Calculation of the Probability

To find the probability that a randomly selected bearing does not have defects, we need to consider the information provided.

According to the given information: - 30% of the bearings produced at the factory have defects. - During quality control, 65% of the defective bearings are identified. - The remaining bearings, which are not identified as defective during quality control, are sold.

To calculate the probability that a randomly selected bearing does not have defects, we can use the following steps:

1. Calculate the probability that a bearing has defects: - 30% of the bearings produced have defects.

2. Calculate the probability that a defective bearing is identified during quality control: - 65% of the defective bearings are identified during quality control.

3. Calculate the probability that a bearing does not have defects: - This can be calculated by subtracting the probability of a defective bearing being identified during quality control from 1.

Let's calculate the probability step by step.

Step 1: Calculate the probability that a bearing has defects

The probability that a bearing has defects is given as 30%.

Probability of a bearing having defects = 30% = 0.30

Step 2: Calculate the probability that a defective bearing is identified during quality control

The probability that a defective bearing is identified during quality control is given as 65%.

Probability of a defective bearing being identified during quality control = 65% = 0.65

Step 3: Calculate the probability that a bearing does not have defects

To calculate the probability that a bearing does not have defects, we subtract the probability of a defective bearing being identified during quality control from 1.

Probability of a bearing not having defects = 1 - Probability of a defective bearing being identified during quality control

Let's calculate this:

Probability of a bearing not having defects = 1 - 0.65 = 0.35

Therefore, the probability that a randomly selected bearing does not have defects is 0.35.

Please note that the calculated probability is rounded to the nearest hundredth, as requested.