Question

Based on the information provided from a test for marijuana use, what is the probability that a randomly selected subject did not use marijuana?

A) 0.202
B) 0.763
C) 0.738
D) 0.798

Answer 1

Without the proper context or data provided in the question snippet, it is not possible to accurately determine the probability of a subject not using marijuana. Probability calculations require specific information about the event in question.

Step-by-step explanation:

The question appears to ask about the probability of a subject not using marijuana, although the proper context or relevant data is not provided in the question snippet. When considering any probability problem, you need specific information about the event in question to determine the correct probability. For example, if test results showed that 20% of subjects used marijuana, then the probability of a randomly chosen subject not having used marijuana would be 80%. However, we cannot assume these values without the actual data.

To calculate probability, we would typically subtract the probability of the event (in this case, marijuana use) from 1 to get the probability of the event not occurring. So, if P(marijuana use) is given, then P(not marijuana use) = 1 - P(marijuana use).

Answer 2

The probability of not using marijuana is
`\(1 - 0.763 = 0.237\)`, making option B the correct choice.

Step-by-step explanation:

The probability that a randomly selected subject did not use marijuana can be calculated by subtracting the probability of marijuana use from 1. In this case, the probability of not using marijuana (P(not using marijuana)) is equal to 1 minus the probability of using marijuana (P(using marijuana)). Therefore, the final answer is P(not using marijuana) = 1 - P(using marijuana).

Now, looking at the provided options, the probability of using marijuana is given as 0.763 (option B). To find the probability of not using marijuana, subtract this value from 1:

`\[ P(not using marijuana) = 1 - P(using marijuana) \]`

`\[ P(not using marijuana) = 1 - 0.763 = 0.237 \]`

Therefore, the correct answer is option B) 0.763, indicating that there is a 76.3% probability that a randomly selected subject did not use marijuana based on the information provided.

In summary, when faced with probability questions, it's essential to recognize the relationship between the event in question and its complement. The complement of an event is simply the probability of that event not occurring. In this case, understanding that P(not using marijuana) = 1 - P(using marijuana) allows for a straightforward calculation, leading to the final answer of 0.763.