In: Statistics and Probability
Are beer, wine, and liquor consumed equally by Americans? A random sample found that out of 647 people, 293 selected beer, 218 selected wine, and 136 selected liquor.
1. What are the null and alternate hypotheses for the chi-square goodness of fit test?
2. What are the expected counts under the null hypothesis?
3. Determine a chi-square test statistic and P value
4. Do you accept or reject the null?
(1)
Ho: The proportion of beer, wine and liquor consumption are equal. Pbeer= Pwine = Pliquor= 0.333
Ha: Some of the population proportions differ from the values stated in the null hypothesis
(2) Expected counts = 216
Category | Observed values (fo) |
Expected Proportions | Expected values (fe) |
(fo-fe)2/ fe |
beer | 293 | 0.333 | 216 | 27.7300 |
wine | 218 | 0.333 | 216 | 0.0252 |
liquor | 136 | 0.333 | 216 | 29.4286 |
Total | 647 | 1 | 647 | 57.1839 |
(3)
(sum of last coloumn in the above table)
df = 3-1 = 2
Level of significance = 0.05 (assuming 0.05 as the same is not mentioned)
p value = 0
(4)
critical = CHISQ.INV.RT(probability,df) = CHISQ.INV.RT(0.05,2) = 5.991
As the stat (57.1839) is greater than critical, we reject the Null hypothesis.
Also as the p value (0) is less than level of significance, we reject the Null hypothesis.