Respuesta :
Answer:
a) Null hypothesis:[tex]\mu \leq 120[/tex]
Alternative hypothesis:[tex]\mu > 120[/tex]
b) [tex]t=\frac{130-120}{\frac{40}{\sqrt{80}}}=2.236[/tex]
The degrees of freedom are given by:
[tex] df = n-1 = 80-1=79[/tex]
The p value for this case taking in count the alternative hypothesis would be:
[tex]p_v =P(t_{79}>2.236)=0.0141[/tex]
Step-by-step explanation:
Information given
[tex]\bar X=130[/tex] represent the sample mean for the amount spent each shopper
[tex]s=40[/tex] represent the sample standard deviation
[tex]n=80[/tex] sample size
[tex]\mu_o =120[/tex] represent the value to verify
t would represent the statistic
[tex]p_v[/tex] represent the p value f
Part a
We want to verify if the shoppers participating in the loyalty program spent more on average than typical shoppers, the system of hypothesis would be:
Null hypothesis:[tex]\mu \leq 120[/tex]
Alternative hypothesis:[tex]\mu > 120[/tex]
The statistic for this case would be given by:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
Replacing the info given we got:
[tex]t=\frac{130-120}{\frac{40}{\sqrt{80}}}=2.236[/tex]
The degrees of freedom are given by:
[tex] df = n-1 = 80-1=79[/tex]
The p value for this case taking in count the alternative hypothesis would be:
[tex]p_v =P(t_{79}>2.236)=0.0141[/tex]