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95% confidence interval of means

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A researcher wants to estimate the difference in the means of two populations. A random sample of 36 items from the first population results in a sample mean of 430 with a sample standard deviation of 120. A random sample of 49 items from the second population results in a sample mean of 460 with a sample standard deviation of 140. From this information, a 95% confidence interval for the difference in population means is?

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(ux - uy) - (x - y ) / √(σx ^2/n1 + σy^2/n2) ~Z(1,0)

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P[ |(ux - uy) - (x - y ) / √(σx ...

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