Respuesta :
Answer:
1.8732, 0.068
Step-by-step explanation:
Given that according to the National Association of Realtors, it took an average of three weeks to sell a home in 2017.
Sample size n = 39
a) [tex]\bar x = 3.6\\s = 2[/tex]
Std error of sample = [tex]\frac{2}{\sqrt{39} } \\=0.3203[/tex]
[tex]H_0: \bar x = 3\\H_a: \bar x \neq 3[/tex]
(Two tailed test at 5% significance level)
Mean difference = 0.6
Since population std deviation is not known, t test to be used.
b) Test statistic t = mean diff/std error =[tex]\frac{0.6}{0.3203 } \\=1.8732[/tex]
df = 38
c) p value = 0.068
From the information given, we have that:
a)
[tex]H_0: \mu = 3[/tex]
[tex]H_a: \mu \neq 3[/tex]
b)
The value of the test statistic is t = 1.873.
c)
The p-value of the test is of 0.0688.
Item a:
At the null hypothesis, it is tested if the mean is the same as the national average of 3, that is:
[tex]H_0: \mu = 3[/tex]
At the alternative hypothesis, it is tested if the mean is different of the national average of 3, that is:
[tex]H_a: \mu \neq 3[/tex]
Item b:
We have the standard deviation for the sample, thus, the t-distribution is used. The test statistic is given by:
[tex]t = \frac{\overline{x} - \mu}{\frac{s}{\sqrt{n}}}[/tex]
The parameters are:
- [tex]\overline{x}[/tex] is the sample mean.
- [tex]\mu[/tex] is the value tested at the null hypothesis.
- s is the standard deviation of the sample.
- n is the sample size.
In this problem, the parameters are:
[tex]\overline{x} = 3.6, \mu = 3, s = 2, n = 39[/tex]
Thus, the value of the test statistic is:
[tex]t = \frac{\overline{x} - \mu}{\frac{s}{\sqrt{n}}}[/tex]
[tex]t = \frac{3.6 - 3}{\frac{2}{\sqrt{39}}}[/tex]
[tex]t = 1.873[/tex]
The value of the test statistic is t = 1.873.
Item c:
We have a two-tailed test(test if the mean is different from a value), with t = 1.873 and 39 - 1 = 38 df.
Using a t-distribution calculator, the p-value is of 0.0688.
The p-value of the test is of 0.0688.
A similar problem is given at https://brainly.com/question/16194574