Answer :
Answer:
Step-by-step explanation:
From the given information:
The null hypothesis: all three brands are equally likely to their expected value
The alternative hypothesis: preferences exist among the three brands i.e. at least one is different from the expected value.
The expected frequency = [tex]f_e[/tex]
The observed frequency = [tex]f_o[/tex]
[tex]f_e[/tex] [tex]f_o[/tex] [tex](f_o- f_e)^2[/tex] [tex]\dfrac{(f_o - f_e)^2}{f_e}[/tex]
37 30 49.00 1.633
21 30 81.00 2.700
32 30 4.00 0.133
[tex]X^2 = \sum\dfrac{(f_o-f_e)^2}{f_e} = 4.47[/tex]
Degree of freedom = [tex](n-1)[/tex]
= 3 -1
= 2
At ∝ = 0.05 and df = 2
The critical value [tex]X^2_{0.05, 2}= 5.99[/tex]
Decision rule:
Since the calculated chi-square is less than the critical value, we do not reject the null hypothesis.
Thus, the null is retained with a calculated chi-square value of 4.47 and a critical chi-square value of 5.99.