A random sample of 16 students selected from the student body of a large university had an average age of 25 years and a standard deviation of 2 years. At 95% confidence, test to determine if the average age of all the students at the university is significantly more than 24.

Respuesta :

Answer:

[tex]t=\frac{25-24}{\frac{2}{\sqrt{16}}}=2[/tex]  

The degrees of freedom are:

[tex] df = n--1=16-1=15[/tex]

Now since we are conducting a right tailed test the p value can be calculated as follows:

[tex]p_v =P(t_{15}>2)=0.0320[/tex]  

Since the p value is lower than the significance level of [tex]\alpha=0.05[/tex] we have enough evidence to conclude that the true mean for the ages is significantly higher than 24

Step-by-step explanation:

Information provided

[tex]\bar X=25[/tex] represent the mean for the ages

[tex]s=2[/tex] represent the sample standard deviation

[tex]n=16[/tex] sample size  

[tex]\mu_o =24[/tex] represent the value to check

[tex]\alpha=0.05[/tex] represent the significance level

t would represent the statistic

[tex]p_v[/tex] represent the p value

Hypothesis to verify

We want to check if the average age of all the students at the university is significantly more than 24, the system of hypothesis would be:  

Null hypothesis:[tex]\mu \leq 24[/tex]  

Alternative hypothesis:[tex]\mu > 24[/tex]  

Since we don't know the population deviation the statistic would be given by:

[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)  

Replacing the data given we got:

[tex]t=\frac{25-24}{\frac{2}{\sqrt{16}}}=2[/tex]  

The degrees of freedom are:

[tex] df = n-1=16-1=15[/tex]

Now since we are conducting a right tailed test the p value can be calculated as follows:

[tex]p_v =P(t_{15}>2)=0.0320[/tex]  

Since the p value is lower than the significance level of [tex]\alpha=0.05[/tex] we have enough evidence to conclude that the true mean for the ages is significantly higher than 24

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