Question

ellen has music practice three days a week. she practices for all of the three days 85% of the time, two days 8% of the time, one day 4% of the time, and no days 3% of the time. one week is selected at random. define the random variable x. \\(\bigcirc\\) x = the number of weeks ellen attends practice for two days \\(\bigcirc\\) x = the number of days ellen attends practice per week \\(\bigcirc\\) x = the number of weeks ellen attends practice for one days \\(\bigcirc\\) x = the number of weeks ellen attends practice for three days \\(\bigcirc\\) x = the number of weeks ellen attends practice for no days

Explanation:

We need to define the random variable \( X \) based on Ellen's music practice. The options about the number of weeks (e.g., number of weeks she attends practice for two days) are incorrect because the probabilities given (85% for three days, 8% for two days, etc.) are about the number of days per week, not the number of weeks. The correct definition should be about the number of days she attends practice per week, as this is what the probabilities are describing (e.g., 85% chance she practices 3 days in a week, 8% chance 2 days, etc.).

Answer:

\( X = \) the number of days Ellen attends practice per week