Respuesta :
The given survey explains the conditional probability.
CONDITIONAL PROBABILITY.
The conditional probability is the probability that is found out with some conditions.
The correct answer is the last option which is again about conditional probability:
Knowing a student’s grade level does not help determine if he or she uses social media.
- The sample space of an experiment is changed when some additional information pertaining to the outcome of the experiment is received.
- The effect of such information is to reduce the sample space by excluding some outcomes as being impossible which before receiving the information were believed possible .
- The probabilities associated with such a reduced sample space are called conditional probabilities.
The students of the reduced sample space i.e. of 9th grade have the probability of 81% who use the social media.
The students of 8th grade that use social media can be greater or less than 81%.
Therefore this experiment does not help determine if he or she uses social media on the basis of his/her grade.
Only the last option is correct.
The conditional probability can be understood by the following.
https://brainly.com/question/10739947
https://brainly.com/question/4403090