Can you help me with this using R:

the file contains four variables: subj: A subject ID pre: The subject's weight in kg, before taking a weight-loss intervention post: The subject's weight in kg, after taking a weight-loss intervention for 6 months cohort: The cohort to which the subject belonged, labeled either 1 or 2 provide a new binary variable called lost5; this variable should contain an array, where an element is 1 if the subject lost at least 5% of their initial weight over the course of the intervention; and 0 otherwise. Are cohort membership and losing at least 5% of one's initial body weight associated, according to these data? Be sure to justify your choice of test and your answer, using a p-value.