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Z test for equality of two proportions.

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The Damon family owns a large grape vinyard in western NY along Lake Erie. The grapevines must be sprayed at the beginning of the growing season to protect against various insects and diseases. Two new insecticides have just been marketed. Perned 5 and Action. To test their effectiveness, three long rows were selected and sprayed with Pernod 5, and three others were sprayed with Action. when the grapes ripened, 400 of the vines treated with Pernod 5 were checked for infestation.likewise, a sample of 400 vines sprayed with Action were checked. The results:

Pernod sample: 400 vines checked 24 infested vines
Action sample: 400 vines checked 40 infested

At the .05 significance level, can we conclude that there is a difference in the proportion of vines infested using pernod 5 as opposed to Action?

Please help me understand how to use the five step hypothesis method to solve this equation as I'm not sure I'm getting it.

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Solution Summary

The solution gives the step by step procedure for comparing the proportions from two populations.Excel template for each problem is also included. This template can be used to obtain the answers of similar problems.

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