Answer:

Now we need to find the p value , we need to take in count that we are conducting a bilateral test so then the p value can be calculated with this probability:

And we can find this p value with the following excel formula for example:
"=2*(T.DIST(-1.576,21,TRUE))"
Explanation:
For this case they want to conduct a test in order to check if the true mean for the smartphone carrier's data speeds is equal to 17 Mbps, so then the system of hypothesis are:
Null hypothesis:

Alternative hypothesis:

The statistic to check this hypothesis is:

Since we don't know the true population deviation. We know that the sample size is equal to n =22, so then we can find the degrees of freedom given by this formula:

After replace in the statistic formula we have the statistic provided:

Now we need to find the p value , we need to take in count that we are conducting a bilateral test so then the p value can be calculated with this probability:

And we can find this p value with the following excel formula for example:
"=2*(T.DIST(-1.576,21,TRUE))"