Safety. Observers in Texas watched children at playin eight communities. Of the 814 children seen biking,roller skating, or skateboarding, only 14% wore a helmet.a) Create and interpret a 95% confidence interval.b) What concerns do you have about this study thatmight make your confidence interval unreliable? c) Suppose we want to do this study again, picking vari-ous communities and locations at random, and hope to end up with a 98% confidence interval having amargin of error of {4,. How many children mustwe observe?

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A:

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A:

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A: We have to find margin of error.

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A:

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A:

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A:

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A:

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Q: if n = 42, p = 0.6 then construct the 98% confidence interval for the population proportion.

A:

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Q: 26.4, 226.9, 227.1, and 228.6.  Student B:  229.5, 226.1, 230.7, 223.8, and 227.5

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2-Proportion Test

In a 2-proportion test, two separate proportions are measured at the same time, and their similarity is evaluated. It is also known as a 2-proportion z-test, and a comparison of two different proportions is done in this method.