Respuesta :
Answer:
The p-value of the test if 0.0131, which is less than the standard significance level of 0.05, meaning that these data indicates that the self-worth of heroin addicts is less than that of the general population.
Step-by-step explanation:
On a test designed to measure self-worth, the mean for the general population is 48.6.
At the null hypothesis, we test if the mean is of 48.6, that is:
[tex]H_0: \mu = 48.6[/tex]
A psychologist suspects that heroin addicts have a different assessment of self-worth than others in the general population. Test if it is lower.
At the alternative hypothesis, we test if the mean is lower, that is:
[tex]H_1: \mu < 48.6[/tex]
The test statistic is:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, s is the standard deviation and n is the size of the sample.
48.6 is tested at the null hypothesis:
This means that [tex]\mu = 48.6[/tex]
The psychologist obtains a random sample of 40 test scores produced by heroin addicts and found the sample mean and the sample standard deviations are 45.5 and 8.5, respectively.
This means that [tex]n = 40, X = 45.5, s = 8.5[/tex]
Value of the test statistic:
[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]
[tex]t = \frac{45.5 - 48.6}{\frac{8.5}{\sqrt{40}}}[/tex]
[tex]t = -2.31[/tex]
P-value of the test:
The p-value of the test is a one-tailed test(mean lower than a value), with t = -2.31 and 40 - 1 = 39 df.
Using a t-distribution calculator, this p-value is of 0.0131.
The p-value of the test if 0.0131, which is less than the standard significance level of 0.05, meaning that these data indicates that the self-worth of heroin addicts is less than that of the general population.
