A study was done on the accuracy of advertisements by the five types of electronics stores in a city. On each of the six 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: chain A, chain B, chain C, chain D, and chain E.

The values in the following table represent the number of items that were correctly and incorrectly priced.

Store, correct price, incorrect price

chain A, 89, 10

chain B, 53, 14

chain C, 43, 12

chain D, 32, 13

chain E, 41, 7

Determine, at the 0.05 level of significance, whether this data provides sufficient evidence to conclude that the proportion of correctly priced items differs across chains. Do this by hand, and then check results with Excel. Explain your results.