I was watching an online course on the topic Bayesian Networks and I have a question regarding the calculation of marginal probabilities.
Hier is the given network:
and the corresponding course video can be found here: https://de.coursera.org/lecture/probabilistic-graphical-models/reasoning-patterns-KMjHs
In the slides the tutor gets P(L=1) = 0,5
Could someone explain to me the steps of applying the sum rule in order to get to that answer? Thank you in advance!