Geometry

Question Analysis
This question involves calculating the joint probability of four independent events related to a user's daily check - in on an online learning platform.
The main focus is on applying the multiplication rule for independent events to find the probability that the user checks in on all four days by multiplying the individual probabilities of checking in each day.

Key Concept Explanation
Each day's check - in event is independent, meaning the check - in on one day does not affect the check - in on other days.
For multiple independent events , , , and , the probability of all of them occurring is .
Here, , , , and are the probabilities of checking in on Monday, Tuesday, Wednesday, and Thursday respectively.

Step-by-Step Solution
Identify the individual probabilities: