Answer:
a) [tex]z =\frac{104-106}{\sqrt{\frac{8.4^2}{80} +\frac{7.6^2}{70}}}= -1.53[/tex]
b) [tex]p_v =2*P(z<-1.53)=0.126[/tex]
c) Since the p value is higher than the significance level provided we have enogh evidence to FAIL to reject the null hypothesis and we can't conclude that the true means are different at 5% of significance
Step-by-step explanation:
Information given
[tex]\bar X_{1}= 104[/tex] represent the mean for 1
[tex]\bar X_{2}= 106[/tex] represent the mean for 2
[tex]\sigma_{1}= 8.4[/tex] represent the population standard deviation for 1
[tex]\sigma_{2}= 7.6[/tex] represent the population standard deviation for 2
[tex]n_{1}=80[/tex] sample size for the group 1
[tex]n_{2}=70[/tex] sample size for the group 2
z would represent the statistic
Hypothesis to test
We want to check if the two means for this case are equal or not, the system of hypothesis would be:
H0:[tex]\mu_{1}=\mu_{2}[/tex]
H1:[tex]\mu_{1} \neq \mu_{2}[/tex]
The statistic would be given by:
[tex]z =\frac{\bar X_1-\bar X_2}{\sqrt{\frac{\sigma^2_1^2}{n_1} +\frac{\sigma^2_2^2}{n_2}}}= [/tex](1)
Part a
Replacing we got:
[tex]z =\frac{104-106}{\sqrt{\frac{8.4^2}{80} +\frac{7.6^2}{70}}}= -1.53[/tex]
Part b
The p value would be given by this probability:
[tex]p_v =2*P(z<-1.53)=0.126[/tex]
Part c
Since the p value is higher than the significance level provided we have enogh evidence to FAIL to reject the null hypothesis and we can't conclude that the true means are different at 5% of significance