Answer:
The critical value is ±2.145
Step-by-step explanation:
Consider the provided information.
A researcher matched 30 participants on intelligence (hence 15 pairs of participants).
That means the value of n is 15.
Now find the degree of freedom as: [tex]df=n-1[/tex]
Therefore,
[tex]df=15-1=14[/tex]
It is given that assuming a two-tailed test at a 0.05 level of significance.
α=0.05
[tex]\frac{\alpha}{2}=\frac{0.05}{2}=0.025[/tex]
Now by using t distribution table the critical value is:
[tex]\pm t_{\frac{\alpha}{2},df}=\pm t_{0.025,14}\\\pm t_{0.025,14}\approx\pm2.145[/tex]
Hence, the critical value is ±2.145
