Question

Dr. Pagels is a mammalogist who studies meadow and common voles. He frequently traps the moles and has noticed what appears to be a preference for a peanut butter-oatmeal mixture by the meadow voles vs apple slices are usually used in traps, where the common voles seem to prefer the appe slices. So he conducted a study where he used a peanut butten oatmeal mixture in half the traps and the normal apple slices in his remaining traps to see if there was a food preference between the two different votes

Indicate which of the following is the null hypothesis, and which is the alternate hypothesis
a. There food preferences among vole species are independent of one another.
b. There is a relationship between voles and food preference.
c. To test for independence, we need to calculate the Chi-square statistic.
These are the data that Dr. Pagels collected
meadow voles common voles
apple slices 15 21
peanut butter-oatmeal 25 16

Answer 1

The food preferences among vole species are independent of one another.

Explanation:

The hypothesis can be defined as follows:

H₀: The food preferences among vole species are independent of one another.

Hₐ: There is a relationship between voles and food preference.

The data provided is:

meadow voles common voles

apple slices 15 21

peanut butter-oatmeal 25 16

A Chi-square test for the Goodness of fit will be used.

The expected values are computed using the formula:

`E_(i)=\frac{\text{ith Row Total}* \text{jth Column Total}}{N}`

Consider the Excel sheet attached.

The Chi-square statistic value is 2.861.

Compute the degrees of freedom as follows:

df = (r - 1)(c - 1)

= (2 - 1)(2 - 1)

= 1

Compute the p-value as follows:

`p-value=P(\chi^(2)_((1))>2.861)=\text{CHISQ.DIST.RT(2.861,1)}=0.091`

The p-value = 0.091 > α = 0.05

The null hypothesis will not be rejected.

Thus, it can be concluded that the food preferences among vole species are independent of one another.