A psychologist is interested in knowing whether adults who were bullied as children differ from the general population in terms of their empathy for others. On a questionnaire designed to measure empathy, the mean score for the general population is 30.6. Random sampling of 25 scores obtained from individuals who were bullied yielded a sample mean of 39.5 and a sample standard deviation of 6.6. Test at the .05 level of significance. Suppose that the value of your calculated (obtained) test statistic is 6.74. What is your decision

Respuesta :

Answer:

[tex] t = \frac{39.5-30.6}{\frac{6.6}{\sqrt{25}}}= 6.74[/tex]

The degrees of freedom are given by:

[tex] df =n-1= 25-1=24[/tex]

Now we can calculate the p value with the following probability:

[tex] p_v = 2*P(t_{24}>6.74)= 5.69x10^{-7}[/tex]

And for this case since the p value is lower compared to the significance level [tex]\alpha=0.05[/tex] we can reject the null hypothesis and we can conclude that the true mean for this case is different from 30.6 at the significance level of 0.05

Step-by-step explanation:

For this case we have the following info given:

[tex] \bar X = 39.5[/tex] represent the sample mean

[tex] s =6.6[/tex] represent the sample deviation

[tex]\mu = 30.6[/tex] represent the reference value to test.

[tex] n = 25[/tex] represent the sample size selected

The statistic for this case is given by:

[tex] t =\frac{\bar X -\mu}{\frac{s}{\sqrt{n}}}[/tex]

And replacing we got:

[tex] t = \frac{39.5-30.6}{\frac{6.6}{\sqrt{25}}}= 6.74[/tex]

The degrees of freedom are given by:

[tex] df =n-1= 25-1=24[/tex]

Now we can calculate the p value with the following probability:

[tex] p_v = 2*P(t_{24}>6.74)= 5.69x10^{-7}[/tex]

And for this case since the p value is lower compared to the significance level [tex]\alpha=0.05[/tex] we can reject the null hypothesis and we can conclude that the true mean for this case is different from 30.6 at the significance level of 0.05