Answer:
Degrees of freedom=25
Step-by-step explanation:
The formula for degree of freedom for two population sample is :
Degree of freedom=n1 + n2 - 2
N1= first sample
n2=second sample
According to the question, n1=15 and n2=12
So,
Degree of freedom= 15 + 12 - 2⇒ 25