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Statistics: Accuracy of Prices and Advertisements

See the attached file.
A study was done on the accuracy of newspaper advertisements by the five types of food stores in a southeastern city. On each of four days, items were randomly selected from the advertisements for each type of store and the actual price was compared to the advertised price. Each of the stores in the city was classified as one of the following types: national, regional chain A, regional chain B, regional chain C, or independent. The values in the following table represent the number of items that were correctly and incorrectly priced.

Determine, at the 0.05 level of significance, whether these data provide sufficient evidence to conclude that the proportion of correctly priced items differs across stores. Make sure you follow, and show, the steps of your hypothesis testing, and then do with Excel. Explain your results.


Solution Preview

Please refer to attached Excel spreadsheet for full solution.

Step 1:
Ho: all the proportions are equal to each other.
Ha: at least two proportions are not equal.

Step 2:
This is a two sided chi square test.
At 0.05 significance level, the degree of freedom is ...

Solution Summary

Accuracy of prices and advertisements in statistics are examined in the solution.