In: Statistics and Probability
A brewery wants to conduct a Marketing campaign. Therefore the marketing department is interested in the unknown Proportion of college students that buy beer. 425 customers were asked, and 351 of them where college students.
a) Calculate the 99% Confidence Interval for the unknown proportion of buyers that are college students
b) In order to conduct the campaign, the executive board demands, that more than 85% of the customers are college students. Test if this level is fulfilled up until Alpha=10%
Given : n=425 , X=351 , The sample proportion is , p=X/n=351*425=0.5906
Now , ; From Z-table
a) Therefore , the 99% Confidence Interval for the unknown proportion of buyers that are college students is ,
b) Hypothesis: Vs
The test statistic is ,
The critical value is ,
; From Z-table
Decision : Here , the value of the test statistic does not lies in the rejection region.
Therefore , fail to reject Ho.
Conclusion : Hence , there is not sufficient evidence to support the claim that the more than 85% of the customers are college students.