Answer:
The degree of freedom for the test is 27.
Step-by-step explanation:
The experiment performed by the researcher is to determine the number of time the rat touches the specific object compared to a different object.
The parameter under study is the mean number of times the rat touches the specific object.
The hypothesis for the test is defined as:
<em>H₀</em>: The mean number of times the rat touches the specific object is not more than that for a different object, i.e. <em>μ </em>≤ <em>μ</em>₀<em>.</em>
<em>Hₐ</em>: The mean number of times the rat touches the specific object is more than that for a different object, i.e. <em>μ </em>> <em>μ</em>₀<em>.</em>
A <em>t</em>-test for single mean is performed.
The information provided is:
<em>α</em> = 0.05
<em>t</em> = 2.842
<em>n</em> = 28
The degrees of freedom for a single mean <em>t</em>-test is:
df = (<em>n</em> - 1)
= 28 - 1
= 27
Thus, the degree of freedom for the test is 27.