Question

На 400 компакт-дисков в среднем приходится 8 бракованных. Какова вероятность, что взятый наугад компакт-диск окажется исправным?

Answer 1

392/400 или 0,98
в общем, чтобы узнать вероятность, нужно число благоприятных (это 400 - 8) разделить на общее кол-во (это 400)

Answer 2

400-8=392 (исправные)

392/400=0.98-вероятность

Answer 3

Calculating the Probability of Getting a Functional Compact Disc

To calculate the probability of randomly selecting a functional compact disc, we can use the given information that on average, 8 out of 400 compact discs are defective.

The probability of selecting a functional compact disc can be calculated using the formula: \[ \text{Probability of selecting a functional CD} = \frac{\text{Number of functional CDs}}{\text{Total number of CDs}} \]

Using the given information: - Number of functional CDs = Total number of CDs - Number of defective CDs - Total number of CDs = 400 - Number of defective CDs = 8

Substituting these values into the formula: \[ \text{Probability of selecting a functional CD} = \frac{400 - 8}{400} \]

Calculating the probability: \[ \text{Probability of selecting a functional CD} = \frac{392}{400} = 0.98 \]

So, the probability of randomly selecting a functional compact disc is 0.98, or 98%.

Conclusion

Based on the given information, the probability of randomly selecting a functional compact disc from the batch of 400 discs is 98%.