Question

We were told this question uses the Chi Square test for either Goodness of Fit or Independence in the following question:

An ABC News poll asked adults whether they felt genetically modified food was safe to eat. 32 percent felt it was safe, 55 percent felt it was not safe, and 13 percent had no opinion. A random sample of 170 adults was asked the same question at the Portland Saturday Market. 53 people felt that genetically modified food was safe, 94 felt it was not safe and 23 had no opinion. At the 0.01 level of significance, is there sufficient evidence to conclude that the proportions differ from those reported in the poll?

Create a frequency table of the data. Then test the claim and summarize your results with a statement. list the hypothesis statements, test statistic, p-value and critical value(s).

Answer 1

Ans:

H₀: The proportions does not differ from those reported in the poll.

H_a: The proportions differ from those reported in the poll.

	fo	pi	fe	(fo-fe)^2/fe
safe	53	0.32	54.4	0.036
not safe	94	0.55	93.5	0.003
no opinion	23	0.13	22.1	0.037
Total	170	1	170	0.075

Test statistic:

Chi square=0.075

df=3-1=2

p-value=chidist(0.075,2)=0.9630

critical chi square value=CHIINV(0.05,2)=5.99

Fail to reject the null hypothesis.

There is not sufficient evidence to conclude that the proportions differ from those reported in the poll.