Respuesta :
Answer:
The pvalue of the test is of 0.0979 > 0.01, which means that we cannot conclude that the mean tuition and fees for private institutions in California is greater than $35,000.
Step-by-step explanation:
Test if the mean tuition and fees for private institutions in California is greater than $35,000.
This means that at the null hypothesis we test if the fee is of $35,000 or less, that is:
[tex]H_0: \mu \leq 35000[/tex]
And at the alternate hypothesis, we test if it is more than this value, that is:
[tex]H_a: \mu > 35000[/tex]
The test statistic is:
As we have the standard deviation of the sample, the t-distribution is used.
[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.
35000 is tested at the null hypothesis:
This means that [tex]\mu = 35000[/tex]
The mean annual tuition and fees in the 2013-2014 academic year for a sample of 13 private colleges in California was $38,000 with a standard deviation of $7900.
This means that [tex]n = 13, X = 38000, s = 7900[/tex]
Value of the test-statistic:
[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]
[tex]t = \frac{38000 - 35000}{\frac{7900}{\sqrt{13}}}[/tex]
[tex]t = 1.37[/tex]
Pvalue of the test and decision:
The pvalue of the test is the probability of finding a mean above 38000, which is the pvalue of t = 1.37, with 13 - 1 = 12 degrees of freedom, using a one-tailed test.
With the help of a calculator, this pvalue is of 0.0979.
The pvalue of the test is of 0.0979 > 0.01, which means that we cannot conclude that the mean tuition and fees for private institutions in California is greater than $35,000.
