Respuesta :
Answer:
The p-value of the test is 0.0119 < 0.06, which means that the data provides statistically significant evidence at the 0.06 level that the average teaching stay in the metro Atlanta area is greater than the state average.
Step-by-step explanation:
The average teaching salary in Georgia is $48,553 per year. The school districts in the metro Atlanta area boast that they pay more.
At the null hypothesis, we test if they pay the average, that is:
[tex]H_0: \mu = 48553[/tex]
At the alternate hypothesis, we test if they pay more, that is:
[tex]H_1: \mu > 48553[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
48553 is tested at the null hypothesis:
This means that [tex]\mu = 48553[/tex]
Sample of 228 teachers from the metro Atlanta area and record their salaries. The sample mean is $49,021, with a standard deviation of $3,127.
This means that [tex]n = 228, X = 49021, \sigma = 3127[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{49021 - 48553}{\frac{3127}{\sqrt{228}}}[/tex]
[tex]z = 2.26[/tex]
P-value of the test and decision:
The p-value of the test is the probability of finding a sample mean above 49021, which is 1 subtracted by the p-value of z = 2.26.
Looking at the z-table, z = 2.26 has a p-value of 0.9881
1 - 0.9881 = 0.0119
The p-value of the test is 0.0119 < 0.06, which means that the data provides statistically significant evidence at the 0.06 level that the average teaching stay in the metro Atlanta area is greater than the state average.
