Respuesta :
Answer:
Null hypothesis:[tex]\mu \geq 4.0[/tex] Â Â
Alternative hypothesis:[tex]\mu < 4.00[/tex] Â Â
[tex]t=\frac{3.48-4.00}{\frac{1.150075}{\sqrt{45}}}=-3.033077[/tex] Â Â
[tex]df=n-1=45-1=44[/tex]
Since is a left-sided test the p value would be: Â Â
[tex]p_v =P(t_{(44)}<-3.033077)=0.002025[/tex] Â Â
If we compare the p value and the significance level given [tex]\alpha=0.05[/tex] we see that [tex]p_v<\alpha[/tex] so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the mean is significantly less than 4.00 at 5% of significance. Â
Step-by-step explanation:
Data given and notation  Â
[tex]\bar X=3.48[/tex] represent the sample mean
[tex]s=1.150075[/tex] represent the sample standard deviation  Â
[tex]n=45[/tex] sample size  Â
[tex]\mu_o =4.00[/tex] represent the value that we want to test Â
[tex]\alpha=0.05[/tex] represent the significance level for the hypothesis test. Â Â
z would represent the statistic (variable of interest) Â Â
[tex]p_v[/tex] represent the p value for the test (variable of interest) Â Â
State the null and alternative hypotheses. Â Â
We need to conduct a hypothesis in order to check if the mean is less than 4.00 : Â Â
Null hypothesis:[tex]\mu \geq 4.0[/tex] Â Â
Alternative hypothesis:[tex]\mu < 4.00[/tex] Â Â
Since we don't know the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by: Â Â
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1) Â Â
t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value". Â Â
Calculate the statistic  Â
We can replace in formula (1) the info given like this: Â Â
[tex]t=\frac{3.48-4.00}{\frac{1.150075}{\sqrt{45}}}=-3.033077[/tex] Â Â
P-value  Â
First we need to calculate the degrees of freedom given by:
[tex]df=n-1=45-1=44[/tex]
Since is a left-sided test the p value would be: Â Â
[tex]p_v =P(t_{(44)}<-3.033077)=0.002025[/tex] Â Â
Conclusion  Â
If we compare the p value and the significance level given [tex]\alpha=0.05[/tex] we see that [tex]p_v<\alpha[/tex] so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the mean is significantly less than 4.00 at 5% of significance. Â Â

[tex]p_v < \alpha[/tex]
so we can conclude that we can reject the null hypothesis, so we can conclude that the mean is significantly less than 4.00 at 5% of significance.
Step-by-step explanation:
Given :
Sample Mean, [tex]\rm \bar {X}[/tex] = Â 3.48
Sample Standard Deviation, s = 1.150075
Sample Size, n = 45 Â
The value that we want to test , [tex]\mu_0 = 4[/tex]
Significance level for the hypothesis test, [tex]\alpha = 0.05[/tex]
Calculation :
Let, z be represent the statistic (variable of interest) and [tex]p_v[/tex] represent the p value for the test (variable of interest)
Now, we need to conduct a hypothesis in order to check if the mean is less than 4 :
Null hypothesis - [tex]\mu \geq 4[/tex] Â Â Â
Alternate hypothesis - Â [tex]\mu < 4[/tex] Â Â
Since we don't know the population deviation, is better apply a t test and is given by: Â Â Â
[tex]\rm t = \dfrac{\bar{X}-\mu_0}{\dfrac{s}{\sqrt{n} }}[/tex] Â
[tex]\rm t = \dfrac{3.48-4}{\dfrac{1.150075}{\sqrt{45} }}[/tex]
Now, calculate the degrees of freedom,
[tex]\rm df = n-1 = 45-1=44[/tex] Â Â
Left-sided test the p value would be,
[tex]\rm p_v = P(t_4_4 < -3.033077) = 0.002025[/tex]
[tex]p_v < \alpha[/tex]
so we can conclude that we can reject the null hypothesis, so we can conclude that the mean is significantly less than 4.00 at 5% of significance.
For more information, refer the link given below
https://brainly.com/question/14790912?referrer=searchResults
