Answer:
B. the results are not statistically significant at level = 0.05, but they are practically significant.
Step-by-step explanation:
Given that the average Math SAT score for all students taking the exam this year is 480 with standard deviation 100.
Sample size n =4
[tex]\bar x =550\\[/tex]
mean difference = 550-480 = 70
Std error of sample = [tex]\frac{100}{\sqrt{4} } =50[/tex]
Since sample size is small t test can be done with df =3
[tex]H_0: \bar x = 480\\H_a: \bar x >480[/tex]
(one tailed test)
t = [tex]\frac{70}{50} =1.4[/tex]
p value =0.128
Since p >0.05 we accept null hypothesis.
B. the results are not statistically significant at level = 0.05, but they are practically significant.
