Answer:

And the variance can be founded like this:



And if we use this formula we got:

So then we have this:

Explanation:
For this case we have the following data given:

We define the random variable T as the total number of hours that the people watch Games of Thrones or star Wars. So then we can define

We can find the expected value of T like this:

And the variance can be founded like this:


We know that the sampel mena is defined as:

And for this case since the sampel large is enough n>30, we have that the distribution for T can be approximated with the normal distribution using the central limit theorem:

We want to calculate the following probability:

We can use the z score formula given by:

And if we use this formula we got:

So then we have this:
