A study is done by a community group in two neighboring colleges to determine which one graduates students with more math classes. College A samples 11 graduates and finds the mean is 4 math classes with a standard deviation of 1.5 math classes. College B samples 9 graduates and finds the mean is 3.5 math classes with a standard deviation of 1 math class. The community group believes that a student who graduates from college A has taken more math classes, on the average. Test at a 10% significance level. Assume the requirements for a valid hypothesis test are satisfied.

Respuesta :

Answer:

[tex]t=\frac{(4-3.5)-0}{\sqrt{\frac{1.5^2}{11}+\frac{1^2}{9}}}}=0.890[/tex]  

The p value for this case would be:

[tex]p_v =P(t_{18}>0.890)=0.193[/tex]  

The p value is higher than the significance level so then we can conclude that we can FAIL to reject the null hypothesis and then the true mean for group A is not significantly higher than the mean for B

Step-by-step explanation:

Information given

[tex]\bar X_{1}=4[/tex] represent the mean for sample A

[tex]\bar X_{2}=3.5[/tex] represent the mean for sample B

[tex]s_{1}=1.5[/tex] represent the sample standard deviation for A

[tex]s_{2}=1[/tex] represent the sample standard deviation for B  

[tex]n_{1}=11[/tex] sample size for the group A

[tex]n_{2}=9[/tex] sample size for the group B  

[tex]\alpha=0.1[/tex] Significance level provided

t would represent the statistic

Hypothesis to test

We want to verify if the student who graduates from college A has taken more math classes, on the average, the system of hypothesis would be:  

Null hypothesis:[tex]\mu_{1}-\mu_{2} \leq 0[/tex]  

Alternative hypothesis:[tex]\mu_{1} - \mu_{2}> 0[/tex]  

The statistic is given by:

[tex]t=\frac{(\bar X_{1}-\bar X_{2})-\Delta}{\sqrt{\frac{s^2_{1}}{n_{1}}+\frac{s^2_{2}}{n_{2}}}}[/tex] (1)  

And the degrees of freedom are given by [tex]df=n_1 +n_2 -2=11+9-2=18[/tex]  

Replacing we got:

[tex]t=\frac{(4-3.5)-0}{\sqrt{\frac{1.5^2}{11}+\frac{1^2}{9}}}}=0.890[/tex]  

The p value for this case would be:

[tex]p_v =P(t_{18}>0.890)=0.193[/tex]  

The p value is higher than the significance level so then we can conclude that we can FAIL to reject the null hypothesis and then the true mean for group A is not significantly higher than the mean for B