Answer:


Explanation:
Experimeto is to throw a coin 7 times and count the number of faces obtained.
So, getting a success means getting a face.
The probability p of obtaining success is:

The probability of obtaining a failure is:

Then we have all the necessary conditions to have a binomial experiment. Therefore we use the following formula:

Where x represents the number of successes. In this case we want the probability that:

Now assuming that the desired probability is:

So:

=


Finally
