Answer:
a. 135 is correct
Explanation:
We have the following information:
dogs lover: 150
cats lover: 120
as the null hypothesis:
H, there are equal number of dogs lover and cats lover, so the expected frequency in each cell will be equal and that is:
f = (150 + 120) / 2
f = 270/2 = 135
so option a. 135 is correct