Answer:
[tex] t_{calc}= \pm 1.576[/tex]
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:
[tex] p_v = 2*P(t_{21}<-1.576) =0.12997[/tex]
And we can find this p value with the following excel formula for example:
"=2*(T.DIST(-1.576,21,TRUE))"
Step-by-step 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: [tex]\mu = 17[/tex]
Alternative hypothesis: [tex]\mu \neq 17[/tex]
The statistic to check this hypothesis is:
[tex] t= \frac{\bar X -\mu}{\frac{s}{\sqrt{n}}}[/tex]
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:
[tex] df = n-1 = 22-1=21[/tex]
After replace in the statistic formula we have the statistic provided:
[tex] t_{calc}= \pm 1.576[/tex]
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:
[tex] p_v = 2*P(t_{21}<-1.576) =0.12997[/tex]
And we can find this p value with the following excel formula for example:
"=2*(T.DIST(-1.576,21,TRUE))"